.diagram-electric-circuit-energy-3d>*{display:none}
.diagram-joule-heating>*{display:none}
.diagram-pumped-storage-3d>*{display:none}
.diagram-energy-resources-3d>*{display:none}
.diagram-energy-transformation-conservation>*{display:none}
.diagram-household-energy>*{display:none}
:root{--ink:#173f59;--muted:#687d8e;--line:#dbe6ed;--blue:#1686c7;--red:#e65b51;--green:#168c73;--paper:#f5f9fb;--white:#fff}*{box-sizing:border-box}html{background:var(--paper)}body{margin:0;color:var(--ink);background:var(--paper);font-family:"Microsoft YaHei","Noto Sans SC",Arial,sans-serif}a{color:inherit;text-decoration:none}button,input{font:inherit}button{cursor:pointer}.site-header{width:min(1500px,calc(100% - 40px));height:72px;display:flex;align-items:center;justify-content:space-between;margin:auto;border-bottom:1px solid var(--line)}.logo{display:flex;align-items:center;gap:11px}.logo-mark{width:38px;height:38px;display:block;border-radius:11px}.logo div{display:grid;gap:2px}.logo b{font-size:16px}.logo small{color:#7890a1;font-size:10px;font-weight:800;letter-spacing:.12em}.site-header nav{display:flex;align-items:center;gap:19px;color:#536b7e;font-size:14px;font-weight:800}.site-header nav a:hover{color:var(--blue)}.site-header nav form{margin:0}.nav-cta,.nav-button{padding:9px 14px;border:1px solid var(--blue);border-radius:8px;color:#fff!important;background:var(--blue)}.nav-button{height:38px}.user-pill{padding:8px 11px;border-radius:8px;color:#28715f;background:#e5f6f0;font-size:12px}

.flash-stack{position:fixed;z-index:30;top:84px;right:24px;display:grid;gap:7px}.flash{max-width:360px;padding:11px 14px;border:1px solid #c7d9e5;border-left:4px solid var(--blue);border-radius:8px;background:#fff;box-shadow:0 8px 25px rgba(25,54,76,.14);font-size:13px;font-weight:700}.flash.error{border-left-color:var(--red)}.flash.success{border-left-color:var(--green)}main{width:min(1500px,calc(100% - 40px));margin:auto}.hero{min-height:355px;display:grid;grid-template-columns:1fr 330px;align-items:center;gap:60px;padding:54px 20px}.eyebrow,.page-heading>p,.auth-card>p,.launch-card>p{margin:0 0 10px;color:var(--blue);font-size:12px;font-weight:900;letter-spacing:.18em}.hero h1{margin:0;font-size:clamp(43px,5vw,72px);line-height:1.08;letter-spacing:-.055em}.hero h1 em{color:var(--red);font-style:normal}.hero-copy{max-width:670px;margin:22px 0 0;color:#617789;font-size:18px;font-weight:600;line-height:1.75}.hero-panel{position:relative;overflow:hidden;padding:29px;border:1px solid #cde0ea;border-radius:20px;color:#fff;background:linear-gradient(145deg,#165478,#168b8b);box-shadow:0 18px 45px rgba(21,90,112,.2)}.hero-panel span{font-size:14px;font-weight:800}.hero-panel b{display:block;margin:8px 0 2px;font:900 74px Georgia,serif}.hero-panel p{margin:0;color:#d5f4f0;font-weight:700}.hero-panel i{position:absolute;right:-35px;bottom:-48px;width:150px;height:150px;border:25px solid rgba(255,255,255,.11);border-radius:50%}

.gallery-head{display:flex;align-items:end;justify-content:space-between;gap:20px;margin:5px 0 20px;padding:0 3px}.gallery-head>div>span{color:var(--green);font-size:13px;font-weight:900;letter-spacing:.15em}.gallery-head h2{margin:5px 0 0;font-size:29px}.gallery-head>p{margin:0;padding:9px 13px;border-radius:8px;color:#796852;background:#fff3db;font-size:13px;font-weight:700}.gallery-head>p b{color:#ba781b}.gallery-head .all-open{color:#176f5d;background:#e5f6f0}.model-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:15px}.model-card{position:relative;overflow:hidden;border:1px solid var(--line);border-radius:16px;background:#fff;box-shadow:0 9px 25px rgba(28,63,89,.055);transition:.2s ease}.model-card:not(.locked):hover{transform:translateY(-4px);box-shadow:0 18px 36px rgba(28,63,89,.12)}.card-visual{position:relative;height:174px;overflow:hidden;background:linear-gradient(150deg,#edf7fb,#f8fbfd)}.visual-top{position:absolute;z-index:3;top:12px;left:13px;right:13px;display:flex;justify-content:space-between}.visual-top span,.visual-top b,.free-badge{padding:5px 8px;border-radius:6px;font-size:10px;font-style:normal;font-weight:900}.visual-top span{color:#1a658d;background:rgba(255,255,255,.86)}.visual-top b{color:#fff;background:#1c5877}.free-badge{position:absolute;z-index:3;right:13px;bottom:11px;color:#fff;background:var(--green)}.card-body{position:relative;min-height:186px;padding:18px}.card-index{position:absolute;top:17px;right:17px;color:#c5d2db;font:900 18px Georgia,serif}.card-body h3{margin:0 38px 8px 0;font-size:19px}.card-body p{min-height:48px;margin:0;color:#667c8e;font-size:13px;line-height:1.65}.card-body>a{display:flex;align-items:center;justify-content:space-between;margin-top:16px;padding-top:12px;border-top:1px solid var(--line);color:var(--blue);font-size:13px;font-weight:900}.card-body>a i{font-size:20px;font-style:normal}.model-card.locked .card-visual,.model-card.locked .card-body{filter:blur(7px);opacity:.58;user-select:none;pointer-events:none}.lock-layer{position:absolute;z-index:8;inset:0;display:flex;align-items:center;justify-content:center;flex-direction:column;background:rgba(241,247,250,.36);backdrop-filter:blur(1px)}.lock-layer>span{width:47px;height:47px;display:grid;place-items:center;border-radius:50%;color:#fff;background:#234e68;font-size:28px;transform:rotate(90deg)}.lock-layer b{margin:10px 0 8px;font-size:15px}.lock-layer a{padding:7px 12px;border-radius:7px;color:#fff;background:var(--blue);font-size:12px;font-weight:900}

.thumbnail{position:absolute;inset:0}.thumbnail .shape{position:absolute;display:block}.thumb-pump .a{left:27%;top:34%;width:34%;height:62%;border:5px solid #226586;border-top:0;border-radius:0 0 13px 13px;background:#8bd5ed}.thumb-pump .b{left:42%;top:16%;width:8%;height:49%;background:#e05e50}.thumb-pump .c{left:19%;bottom:14%;width:23%;height:7px;background:#226586}.thumb-pump .d{left:16%;bottom:8%;width:7px;height:28%;background:#226586}.thumb-lens .a{left:47%;top:25%;width:18px;height:91px;border:3px solid #1585c7;border-radius:50%;background:rgba(94,193,232,.38)}.thumb-lens .b,.thumb-lens .c{left:12%;top:46%;width:72%;height:3px;background:#e45b50;transform-origin:left}.thumb-lens .b{transform:rotate(10deg)}.thumb-lens .c{transform:rotate(-9deg)}.thumb-ray .a{left:10%;top:60%;width:80%;height:4px;background:#22617e}.thumb-ray .b,.thumb-ray .c{left:47%;top:8%;width:4px;height:70%;background:#e85c50;transform-origin:bottom}.thumb-ray .b{transform:rotate(-33deg)}.thumb-ray .c{transform:rotate(39deg);background:#1a8bc8}.thumb-resistor .a{left:17%;top:58%;width:67%;height:24px;border-radius:6px;background:repeating-linear-gradient(90deg,#cf7940 0 6px,#efd6a7 6px 12px)}.thumb-resistor .b{left:18%;top:35%;width:65%;height:5px;background:#275c78}.thumb-resistor .c{left:50%;top:28%;width:12px;height:54px;border-radius:5px;background:#e4554b}.thumb-circuit .a{left:17%;top:26%;width:65%;height:86px;border:4px solid #2473a1;border-radius:12px}.thumb-circuit .b,.thumb-circuit .c{top:47%;width:38px;height:38px;border:4px solid #de9e2e;border-radius:50%;background:#fff4ae;box-shadow:0 0 18px rgba(238,179,53,.5)}.thumb-circuit .b{left:25%}.thumb-circuit .c{right:25%}.thumb-lever .a{left:14%;top:52%;width:72%;height:9px;border-radius:5px;background:#d17642;transform:rotate(-7deg)}.thumb-lever .b{left:44%;top:56%;width:0;height:0;border-left:27px solid transparent;border-right:27px solid transparent;border-bottom:48px solid #2c718d}.thumb-lever .c,.thumb-lever .d{top:33%;width:18px;height:38px;background:#e4524d}.thumb-lever .c{left:24%}.thumb-lever .d{right:21%;height:28px}.thumb-float .a,.thumb-pressure .a{left:18%;top:27%;width:65%;height:112px;border:5px solid #286781;border-top:0;background:linear-gradient(transparent 18%,rgba(54,167,221,.48) 18%)}.thumb-float .b{left:41%;top:55%;width:55px;height:48px;border-radius:9px;background:#e1a04c}.thumb-pressure .b{left:49%;top:59%;width:25px;height:25px;border:5px solid #e15149;border-radius:50%;background:#fff}.thumb-pressure .c{left:53%;top:31%;width:3px;height:53px;border-left:3px dashed #e15149}.thumb-thermo .a{left:47%;top:22%;width:16px;height:88px;border:4px solid #386b85;border-radius:9px;background:#fff}.thumb-thermo .b{left:43%;top:68%;width:39px;height:39px;border-radius:50%;background:#e75149}.thumb-thermo .c{left:52%;top:37%;width:6px;height:62px;background:#e75149}.thumb-atmosphere .a{left:24%;top:30%;width:54%;height:91px;border:5px solid #28677f;border-radius:12px;background:#d8eff7}.thumb-atmosphere .b{left:32%;top:17%;width:38%;height:17px;border-radius:8px;background:#e35b50}.thumb-atmosphere .c{left:49%;top:6%;width:5px;height:48px;background:#506e7c}.thumb-incline .a{left:15%;bottom:24%;width:0;height:0;border-left:0 solid transparent;border-right:215px solid transparent;border-bottom:105px solid #dce5ea}.thumb-incline .b{left:44%;top:42%;width:49px;height:40px;border-radius:7px;background:#e39b43;transform:rotate(-26deg)}.thumb-incline .c{left:55%;top:24%;width:82px;height:4px;background:#1681c8;transform:rotate(-26deg)}.thumb-pulley .a,.thumb-pulley .b{top:26%;width:45px;height:45px;border:6px solid #2b6d8b;border-radius:50%;background:#fff}.thumb-pulley .a{left:31%}.thumb-pulley .b{right:29%;top:57%}.thumb-pulley .c{left:38%;top:22%;width:32%;height:99px;border-left:4px solid #e05a4f;border-right:4px solid #e05a4f}.thumb-energy .a{left:14%;top:35%;width:72%;height:94px;border-bottom:7px solid #2b718f;border-radius:0 0 50% 50%}.thumb-energy .b{left:22%;top:28%;width:34px;height:34px;border-radius:50%;background:#e25a4f}.thumb-energy .c{right:20%;top:22%;width:48px;height:5px;background:#1688c9;transform:rotate(-25deg)}.thumb-inertia .a{left:23%;top:57%;width:58%;height:45px;border-radius:8px;background:#28769d}.thumb-inertia .a::before,.thumb-inertia .a::after{content:"";position:absolute;bottom:-15px;width:24px;height:24px;border-radius:50%;background:#344e5d}.thumb-inertia .a::before{left:12px}.thumb-inertia .a::after{right:12px}.thumb-inertia .b{left:45%;top:31%;width:42px;height:47px;border-radius:7px;background:#e3a04b}.thumb-inertia .c{right:11%;top:48%;width:62px;height:5px;background:#e0524a}

.teaching-note{display:flex;align-items:center;gap:15px;margin-top:20px;padding:16px 20px;border-radius:11px;color:#205e50;background:#e7f6f1;font-size:14px;font-weight:700}.teaching-note span{padding:7px 10px;border-radius:6px;color:#fff;background:var(--green);font-weight:900}.teaching-note p{margin:0}.center-page{min-height:calc(100vh - 145px);display:grid;place-items:center;padding:40px 0}.auth-card,.launch-card{width:min(460px,100%);padding:34px;border:1px solid var(--line);border-radius:18px;background:#fff;box-shadow:0 16px 42px rgba(25,60,85,.1)}.auth-mark{width:48px;height:48px;display:grid;place-items:center;margin-bottom:18px;border-radius:13px;color:#fff;background:var(--blue);font-size:22px;font-weight:900}.auth-card h1,.launch-card h1{margin:0 0 7px;font-size:28px}.auth-card>span,.launch-card>span{color:#6b8091;font-size:14px}.auth-card form{display:grid;gap:13px;margin-top:23px}.auth-card label{display:grid;gap:6px;color:#536a7c;font-size:12px;font-weight:900}.auth-card input,.user-row input{height:43px;padding:0 12px;border:1px solid #cbd9e3;border-radius:8px;outline:0;color:var(--ink);background:#fbfdfe}.auth-card input:focus,.user-row input:focus{border-color:var(--blue);box-shadow:0 0 0 3px rgba(22,134,199,.12)}.auth-card form>button{height:45px;border:0;border-radius:8px;color:#fff;background:var(--blue);font-weight:900}.auth-switch{margin-top:18px;color:#718596;text-align:center;font-size:13px}.auth-switch a{color:var(--blue);font-weight:900}.page-heading{padding:48px 3px 25px}.page-heading h1{margin:0 0 7px;font-size:34px}.page-heading span{color:#667c8e}.user-table{overflow:hidden;border:1px solid var(--line);border-radius:14px;background:#fff}.table-head,.user-row{display:grid;grid-template-columns:1.1fr .6fr 1fr 1.5fr;align-items:center;gap:14px;padding:13px 18px}.table-head{color:#6b8091;background:#eef5f8;font-size:12px;font-weight:900}.user-row{border-top:1px solid var(--line)}.user-row>div{display:grid}.user-row small{color:#91a1ad}.role{width:max-content;padding:5px 8px;border-radius:6px;color:#4d6779;background:#edf2f5;font-size:11px;font-weight:900}.role.admin{color:#9b6421;background:#fff0d5}.user-row time{color:#6d8293;font-size:12px}.user-row form{display:grid;grid-template-columns:1fr auto;gap:7px}.user-row button{border:0;border-radius:7px;color:#fff;background:var(--blue);font-weight:800}.launch-card{text-align:center}.loader{height:52px;display:flex;align-items:end;justify-content:center;gap:6px;margin-bottom:18px}.loader i{width:8px;border-radius:5px;background:var(--blue);animation:pulse 1s infinite ease-in-out}.loader i:nth-child(1){height:22px}.loader i:nth-child(2){height:42px;animation-delay:.15s}.loader i:nth-child(3){height:30px;animation-delay:.3s}@keyframes pulse{50%{opacity:.35;transform:scaleY(.65)}}.launch-card a{display:inline-block;margin-top:22px;padding:10px 14px;border-radius:8px;color:#fff;background:var(--blue);font-size:13px;font-weight:900}.error-card>h1{font:900 70px Georgia,serif;color:var(--red)}footer{width:min(1500px,calc(100% - 40px));display:flex;justify-content:center;gap:12px;margin:28px auto 0;padding:24px 0;border-top:1px solid var(--line);color:#718596;font-size:12px}footer b{color:#4d6678}

@media(max-width:1180px){.model-grid{grid-template-columns:repeat(3,1fr)}}@media(max-width:900px){.site-header nav>a:not(.nav-cta),.user-pill{display:none}.hero{grid-template-columns:1fr;padding:45px 5px}.hero-panel{display:none}.model-grid{grid-template-columns:repeat(2,1fr)}.table-head{display:none}.user-row{grid-template-columns:1fr 1fr}.user-row form{grid-column:1/3}}@media(max-width:600px){.site-header,main,footer{width:min(100% - 18px,580px)}.site-header nav{gap:8px}.logo small{display:none}.hero{min-height:310px}.hero h1{font-size:42px}.hero-copy{font-size:15px}.gallery-head{align-items:flex-start;flex-direction:column}.model-grid{grid-template-columns:1fr}.card-visual{height:190px}.auth-card,.launch-card{padding:26px 19px}.user-row{grid-template-columns:1fr}.user-row form{grid-column:1}.teaching-note{align-items:flex-start;flex-direction:column;gap:8px}footer{display:block;text-align:center;line-height:1.8}}

 .model-card-link{display:block;color:inherit}.card-action{display:flex;align-items:center;justify-content:space-between;margin-top:16px;padding-top:12px;border-top:1px solid var(--line);color:var(--blue);font-size:13px;font-weight:900}.card-action i{font-size:20px;font-style:normal}

.admin-section{margin:0 0 18px;padding:20px;border:1px solid var(--line);border-radius:14px;background:#fff}.admin-section-head{display:flex;align-items:end;justify-content:space-between;gap:18px;margin-bottom:13px}.admin-section-head span{color:var(--green);font-size:11px;font-weight:900;letter-spacing:.14em}.admin-section-head h2{margin:4px 0 0;font-size:22px}.admin-section-head small{color:#778b9a;font-size:12px}.visitor-table{overflow-x:auto;border:1px solid var(--line);border-radius:10px}.visitor-head,.visitor-row{display:grid;grid-template-columns:1.05fr 1.45fr .55fr .65fr 1.15fr 1.15fr;align-items:center;gap:12px;min-width:980px;padding:11px 14px}.visitor-head{color:#6b8091;background:#eef5f8;font-size:11px;font-weight:900}.visitor-row{border-top:1px solid var(--line);font-size:13px}.visitor-row strong{color:var(--blue);font-size:18px}.visitor-row span{color:#6d8291}.visitor-row .visitor-location{color:#315f79;font-weight:700;line-height:1.45}.visitor-row time{color:#6d8291;font-size:11px}.visitor-row code{color:#4d6d82;font-family:Consolas,monospace;font-size:12px}.visitor-table.recent .visitor-head,.visitor-table.recent .visitor-row{grid-template-columns:1.15fr 1fr 1.4fr .75fr 1.5fr;min-width:900px}.empty-row{padding:22px;color:#8294a1;text-align:center;font-size:13px}

/* 锁定模型保持缩略图清晰，只用半透明提示层说明登录要求。 */

.model-card.locked .card-visual,.model-card.locked .card-body{filter:none;opacity:1}

.lock-layer{background:rgba(241,247,250,.68);backdrop-filter:none}

/* 新增模型的极简卡片缩略图。 */

.thumb-electromagnet .a{left:31%;top:23%;width:38%;height:78%;border:6px solid #c86c3e;border-left-width:12px;border-right-width:12px;border-radius:18px;background:repeating-linear-gradient(0deg,transparent 0 10px,#e28b5a 11px 15px)}.thumb-electromagnet .b{left:42%;top:18%;width:16%;height:84%;background:#6c7d87;border-radius:7px}.thumb-electromagnet .c{left:13%;top:62%;width:27%;height:4px;background:#2d73a0;transform:rotate(-24deg)}.thumb-electromagnet .d{right:13%;top:62%;width:27%;height:4px;background:#2d73a0;transform:rotate(24deg)}

.thumb-engine .a{left:25%;top:26%;width:50%;height:61%;border:5px solid #2a6d87;border-radius:8px;background:#d9edf3}.thumb-engine .b{left:37%;top:34%;width:26%;height:25%;border-radius:4px;background:#e4a04c}.thumb-engine .c{left:48%;top:12%;width:5px;height:28%;background:#df5a4f}.thumb-engine .d{left:48%;bottom:8%;width:5px;height:24%;background:#df5a4f}

.thumb-generator .a{left:34%;top:26%;width:32%;height:52%;border:6px solid #2f6f8e;border-radius:50%;background:#fff}.thumb-generator .b{left:48%;top:12%;width:5px;height:28%;background:#e05b4f;transform-origin:bottom;transform:rotate(28deg)}.thumb-generator .c{left:17%;top:65%;width:66%;height:5px;background:#2f75a0}.thumb-generator .d{left:45%;top:65%;width:10%;height:22%;border:4px solid #e2a139;border-top:0}



/* 首页缩略图使用规范化的小型原理图：统一线宽，只保留决定物理结构的关键构件。 */

.thumbnail-diagram{--dl:#225c78;--db:#1686c7;--dr:#e65b51;--dg:#e0a03c;--dw:#8bd7ed;position:absolute;inset:0;overflow:hidden}

.thumbnail-diagram .part{position:absolute;display:block;box-sizing:border-box}

.thumbnail-diagram .part::before,.thumbnail-diagram .part::after{position:absolute;box-sizing:border-box;content:""}



/* 活塞泵：水源—进水管—下阀—活塞阀—出水嘴构成连续水路。 */

.diagram-pump .p1{left:39%;top:32%;width:25%;height:61%;border:4px solid var(--dl);border-radius:5px 5px 10px 10px;background:linear-gradient(to top,rgba(75,185,222,.62) 0 53%,transparent 53%)}

.diagram-pump .p1::before{left:7%;top:25%;width:86%;height:6px;border-radius:4px;background:var(--dr)}

.diagram-pump .p1::after{left:34%;top:70%;width:32%;height:5px;border-radius:4px;background:var(--dr);transform:rotate(-18deg);transform-origin:right}

.diagram-pump .p2{left:50%;top:12%;width:5px;height:37%;border-radius:3px;background:var(--dr)}

.diagram-pump .p2::before{left:-27px;top:0;width:59px;height:6px;border-radius:5px;background:var(--dr)}

.diagram-pump .p3{left:22%;top:67%;width:19%;height:23%;border-left:5px solid var(--dl);border-bottom:5px solid var(--dl);border-radius:0 0 0 9px}

.diagram-pump .p4{left:9%;bottom:6%;width:29%;height:27%;border:4px solid var(--dl);border-top:0;border-radius:0 0 9px 9px;background:linear-gradient(to top,rgba(75,185,222,.62) 0 73%,transparent 73%)}

.diagram-pump .p5{left:63%;top:45%;width:24%;height:16%;border-top:5px solid var(--dl);border-right:5px solid var(--dl);border-radius:0 9px 0 0}

.diagram-pump .p5::after{right:-5px;top:11px;width:5px;height:25px;border-radius:0 0 5px 5px;background:var(--db);box-shadow:0 20px 0 -1px rgba(22,134,199,.45)}

.diagram-pump .p6{left:44%;top:54%;width:14px;height:10px;border-top:4px solid var(--dr);transform:rotate(-18deg)}

.diagram-pump .p6::after{right:-2px;top:-7px;border-left:6px solid transparent;border-right:6px solid transparent;border-bottom:7px solid var(--dr)}



/* 凸透镜：主轴、物箭头、光屏与两条典型成像光线。 */

.diagram-lens .p1{left:48%;top:19%;width:20px;height:111px;border:3px solid var(--db);border-radius:50%;background:rgba(90,194,232,.3)}

.diagram-lens .p2{left:10%;top:58%;width:80%;border-top:2px dashed #7893a3}

.diagram-lens .p3{left:24%;top:35%;width:4px;height:41px;background:var(--dr)}

.diagram-lens .p3::before{left:-7px;top:-1px;border-left:9px solid transparent;border-right:9px solid transparent;border-bottom:0;border-top:12px solid var(--dr)}

.diagram-lens .p4{right:14%;top:23%;width:5px;height:105px;border-radius:3px;background:#7893a3}

.diagram-lens .p5{left:25%;top:35%;width:24%;border-top:3px solid var(--dr)}

.diagram-lens .p5::after{left:100%;top:-2px;width:124%;border-top:3px solid var(--dr);transform:rotate(19deg);transform-origin:left}

.diagram-lens .p6{left:25%;top:35%;width:58%;border-top:3px solid var(--db);transform:rotate(10deg);transform-origin:left}



/* 反射与折射：法线垂直界面，反射角等于入射角，折射光进入下方介质。 */

.diagram-ray .p1{left:9%;top:57%;width:82%;height:4px;background:var(--dl)}

.diagram-ray .p1::after{left:0;top:4px;width:100%;height:53px;background:rgba(86,188,226,.18)}

.diagram-ray .p2{left:50%;top:13%;height:126px;border-left:3px dashed #8aa0ad}

.diagram-ray .p3{left:23%;top:18%;width:34%;border-top:4px solid var(--dr);transform:rotate(38deg);transform-origin:right}

.diagram-ray .p3::after{right:5px;top:-8px;border-left:9px solid var(--dr);border-top:6px solid transparent;border-bottom:6px solid transparent}

.diagram-ray .p4{left:50%;top:57%;width:34%;border-top:4px solid var(--db);transform:rotate(-38deg);transform-origin:left}

.diagram-ray .p5{left:50%;top:57%;width:31%;border-top:4px solid var(--dg);transform:rotate(59deg);transform-origin:left}

.diagram-ray .p6{left:44%;top:49%;width:18px;height:18px;border:2px solid #7a93a3;border-left:0;border-bottom:0;border-radius:0 18px 0 0}



/* 滑动变阻器：电阻丝、瓷筒、滑片、触点和四个接线柱位置明确。 */

.diagram-resistor .p1{left:17%;top:57%;width:66%;height:27px;border:3px solid #b86d3f;border-radius:8px;background:#f3ddb6}

.diagram-resistor .p2{left:19%;top:60%;width:62%;height:21px;background:repeating-linear-gradient(90deg,transparent 0 5px,#c56d38 5px 8px)}

.diagram-resistor .p3{left:20%;top:35%;width:61%;height:5px;border-radius:4px;background:var(--dl)}

.diagram-resistor .p4{left:49%;top:29%;width:10px;height:54px;border-radius:5px;background:var(--dr)}

.diagram-resistor .p4::after{left:-5px;bottom:-3px;width:20px;height:8px;border-radius:4px;background:var(--dr)}

.diagram-resistor .p5,.diagram-resistor .p6{top:76%;width:12px;height:12px;border:3px solid var(--dl);border-radius:50%;background:#fff}

.diagram-resistor .p5{left:12%;box-shadow:0 -65px 0 -3px #fff,0 -65px 0 0 var(--dl)}

.diagram-resistor .p6{right:12%;box-shadow:0 -65px 0 -3px #fff,0 -65px 0 0 var(--dl)}



/* 串并联：缩略图采用并联结构，两只灯泡各占一条独立支路。 */

.diagram-circuit .p1{left:14%;top:25%;width:72%;height:104px;border:4px solid var(--dl);border-radius:10px}

.diagram-circuit .p2,.diagram-circuit .p3{left:20%;width:60%;border-top:4px solid var(--dl)}

.diagram-circuit .p2{top:47%}.diagram-circuit .p3{top:70%}

.diagram-circuit .p2::after,.diagram-circuit .p3::after{left:calc(50% - 18px);top:-20px;width:36px;height:36px;border:4px solid var(--dg);border-radius:50%;background:#fff8cf;box-shadow:inset 0 0 0 5px #fff}

.diagram-circuit .p2::before,.diagram-circuit .p3::before{z-index:2;left:calc(50% - 7px);top:-8px;width:14px;height:12px;border-bottom:3px solid var(--dg);transform:rotate(45deg)}

.diagram-circuit .p4{left:12%;top:54%;width:9px;height:32px;background:var(--paper);border-top:4px solid var(--dr);border-bottom:8px solid var(--dr)}

.diagram-circuit .p5,.diagram-circuit .p6{top:45%;width:9px;height:9px;border-radius:50%;background:var(--dl);box-shadow:0 40px 0 var(--dl)}

.diagram-circuit .p5{left:18.5%}.diagram-circuit .p6{right:18.5%}



/* 杠杆：支点位于杆下，两侧力均通过悬挂线作用在杆上。 */

.diagram-lever .p1{left:13%;top:52%;width:74%;height:9px;border-radius:6px;background:#c97843;transform:rotate(-7deg)}

.diagram-lever .p2{left:44%;top:54%;border-left:25px solid transparent;border-right:25px solid transparent;border-bottom:44px solid var(--dl);border-top:0}

.diagram-lever .p3,.diagram-lever .p4{width:4px;background:var(--dl)}

.diagram-lever .p3{left:25%;top:39%;height:35px}.diagram-lever .p4{right:25%;top:34%;height:30px}

.diagram-lever .p3::after,.diagram-lever .p4::after{left:-13px;bottom:-27px;width:30px;height:25px;border-radius:5px;background:var(--dr)}

.diagram-lever .p5{left:21%;top:20%;height:28px;border-left:4px solid var(--db)}

.diagram-lever .p5::after{left:-7px;bottom:-3px;border-left:7px solid transparent;border-right:7px solid transparent;border-top:10px solid var(--db)}

.diagram-lever .p6{left:47%;top:81%;width:45%;border-top:3px solid #91a3ae}



/* 浮沉：物体部分露出液面，浮力与重力沿同一竖直线反向。 */

.diagram-float .p1{left:19%;top:28%;width:62%;height:112px;border:4px solid var(--dl);border-top:0;border-radius:0 0 9px 9px}

.diagram-float .p2{left:21%;top:49%;width:58%;height:73px;background:rgba(75,185,222,.45)}

.diagram-float .p3{left:42%;top:39%;width:50px;height:47px;border:3px solid #be7639;border-radius:7px;background:#e7aa55}

.diagram-float .p4,.diagram-float .p5{left:50%;width:4px}

.diagram-float .p4{top:24%;height:36px;background:var(--db)}

.diagram-float .p4::before{left:-7px;top:-1px;border-left:9px solid transparent;border-right:9px solid transparent;border-bottom:11px solid var(--db)}

.diagram-float .p5{top:64%;height:36px;background:var(--dr)}

.diagram-float .p5::after{left:-7px;bottom:-1px;border-left:9px solid transparent;border-right:9px solid transparent;border-top:11px solid var(--dr)}

.diagram-float .p6{left:24%;top:47%;width:52%;border-top:3px solid var(--db)}



/* 液体压强：同一液体中深处喷流更远，并标出深度方向。 */
/* 新版使用真实3D探头与U形管场景，保留原kind以兼容章目录。 */
.diagram-pressure{background-image:var(--thumbnail-load,url("/static/model-thumbnails/liquid-pressure.png"));background-size:cover;background-position:center}.diagram-pressure .part{display:none}

.diagram-pressure .p1{left:17%;top:27%;width:51%;height:114px;border:4px solid var(--dl);border-top:0;border-radius:0 0 8px 8px}

.diagram-pressure .p2{left:19%;top:43%;width:47%;height:84px;background:rgba(75,185,222,.47);border-top:3px solid var(--db)}

.diagram-pressure .p3,.diagram-pressure .p4{left:67%;height:4px;border-radius:0 5px 5px 0;background:var(--db)}

.diagram-pressure .p3{top:56%;width:16%}.diagram-pressure .p4{top:75%;width:27%}

.diagram-pressure .p3::before,.diagram-pressure .p4::before{left:-5px;top:-2px;width:8px;height:8px;border:2px solid var(--dl);border-radius:50%;background:#fff}

.diagram-pressure .p5{left:27%;top:44%;height:52%;border-left:3px dashed var(--dr)}

.diagram-pressure .p5::after{left:-7px;bottom:-1px;border-left:7px solid transparent;border-right:7px solid transparent;border-top:10px solid var(--dr)}

.diagram-pressure .p6{left:25%;top:69%;width:10px;border-top:3px solid var(--dr)}



/* 物态变化：烧杯中冰水受热，温度计独立插入且不接触杯底。 */

.diagram-thermo .p1{left:31%;top:35%;width:42%;height:86px;border:4px solid var(--dl);border-top:0;border-radius:0 0 10px 10px;background:linear-gradient(to top,rgba(75,185,222,.42) 0 54%,transparent 54%)}

.diagram-thermo .p2{left:45%;top:16%;width:13px;height:88px;border:3px solid var(--dl);border-radius:8px;background:#fff}

.diagram-thermo .p2::before{left:2px;bottom:5px;width:3px;height:58px;background:var(--dr)}

.diagram-thermo .p2::after{left:-3px;bottom:-9px;width:13px;height:13px;border-radius:50%;background:var(--dr)}

.diagram-thermo .p3,.diagram-thermo .p4{top:68%;width:25px;height:20px;border:2px solid #70a9bc;background:rgba(255,255,255,.7);transform:rotate(12deg)}

.diagram-thermo .p3{left:36%}.diagram-thermo .p4{left:53%;transform:rotate(-9deg)}

.diagram-thermo .p5{left:37%;bottom:6%;width:31%;height:9px;border-radius:50%;background:var(--dr)}

.diagram-thermo .p6{left:49%;bottom:12%;border-left:11px solid transparent;border-right:11px solid transparent;border-bottom:25px solid #f09b3c}



/* 大气压：托里拆利装置，封闭玻璃管中的液柱高于槽内液面。 */

.diagram-atmosphere .p1{left:24%;bottom:8%;width:53%;height:37px;border:4px solid var(--dl);border-radius:4px 4px 10px 10px;background:rgba(75,185,222,.46)}

.diagram-atmosphere .p2{left:45%;top:15%;width:18px;height:119px;border:4px solid var(--dl);border-bottom:0;border-radius:9px 9px 0 0;background:#fff}

.diagram-atmosphere .p3{left:49%;top:42%;width:10px;height:85px;background:rgba(75,185,222,.72)}

.diagram-atmosphere .p4{left:61%;top:42%;height:67px;border-left:3px solid var(--dr)}

.diagram-atmosphere .p4::before,.diagram-atmosphere .p4::after{left:-6px;border-left:6px solid transparent;border-right:6px solid transparent}

.diagram-atmosphere .p4::before{top:-1px;border-bottom:9px solid var(--dr)}.diagram-atmosphere .p4::after{bottom:-1px;border-top:9px solid var(--dr)}

.diagram-atmosphere .p5{left:44%;top:17%;width:25px;height:20px;background:linear-gradient(#eef5f8,#fff)}

.diagram-atmosphere .p6{left:65%;top:60%;color:var(--dr);font:bold 15px Georgia,serif}.diagram-atmosphere .p6::after{content:"h"}



/* 斜面：高度线竖直，拉力平行斜面，支持力垂直斜面。 */

.diagram-incline .p1{left:15%;bottom:17%;width:72%;height:94px;background:#dfe9ee;clip-path:polygon(0 100%,100% 100%,100% 0)}

.diagram-incline .p1::after{left:0;bottom:0;width:100%;height:5px;background:var(--dl);transform:rotate(-25deg);transform-origin:right}

.diagram-incline .p2{left:51%;top:42%;width:48px;height:38px;border:3px solid #bd773c;border-radius:6px;background:#e5a24e;transform:rotate(-25deg)}

.diagram-incline .p3{left:58%;top:27%;width:27%;border-top:4px solid var(--db);transform:rotate(-25deg);transform-origin:left}

.diagram-incline .p3::after{right:-2px;top:-8px;border-left:11px solid var(--db);border-top:6px solid transparent;border-bottom:6px solid transparent}

.diagram-incline .p4{right:13%;top:29%;height:55%;border-left:3px dashed var(--dr)}

.diagram-incline .p5{left:61%;top:24%;height:31px;border-left:4px solid var(--dr);transform:rotate(25deg)}

.diagram-incline .p5::before{left:-7px;top:-1px;border-left:7px solid transparent;border-right:7px solid transparent;border-bottom:10px solid var(--dr)}

.diagram-incline .p6{right:10%;bottom:15%;width:77%;border-top:3px solid #91a3ae}



/* 滑轮组：绳端固定后绕过动滑轮，再跨过定滑轮，重物挂在动滑轮轴上。 */

.diagram-pulley .p1,.diagram-pulley .p2{width:42px;height:42px;border:5px solid var(--dl);border-radius:50%;background:#fff}

.diagram-pulley .p1{left:57%;top:25%}.diagram-pulley .p2{left:31%;top:56%}

.diagram-pulley .p1::after,.diagram-pulley .p2::after{left:13px;top:13px;width:6px;height:6px;border-radius:50%;background:var(--dl)}

.diagram-pulley .p3{left:28%;top:22%;width:42%;height:73px;border-left:4px solid var(--dr);border-bottom:4px solid var(--dr);border-right:4px solid var(--dr);border-radius:0 0 24px 24px}

.diagram-pulley .p3::before{left:-8px;top:-7px;width:13px;height:9px;border-radius:3px;background:var(--dl)}

.diagram-pulley .p4{left:37%;top:79%;width:28px;height:25px;border-radius:4px;background:var(--dg)}

.diagram-pulley .p4::before{left:12px;top:-16px;width:4px;height:17px;background:var(--dl)}

.diagram-pulley .p5{left:70%;top:45%;height:49px;border-left:4px solid var(--db)}

.diagram-pulley .p5::after{left:-7px;bottom:-1px;border-left:7px solid transparent;border-right:7px solid transparent;border-top:10px solid var(--db)}

.diagram-pulley .p6{left:19%;top:20%;width:61%;border-top:4px solid #8096a4}



/* 机械能：小车位于高处轨道，速度方向沿轨道切线。 */

.diagram-energy .p1{left:11%;top:33%;width:78%;height:94px;border:6px solid var(--dl);border-top:0;border-radius:0 0 48% 48%}

.diagram-energy .p2{left:19%;top:29%;width:38px;height:24px;border-radius:7px;background:var(--dr);transform:rotate(14deg)}

.diagram-energy .p2::before,.diagram-energy .p2::after{bottom:-7px;width:11px;height:11px;border:2px solid #fff;border-radius:50%;background:#385363}.diagram-energy .p2::before{left:3px}.diagram-energy .p2::after{right:3px}

.diagram-energy .p3{left:29%;top:26%;width:23%;border-top:4px solid var(--db);transform:rotate(14deg);transform-origin:left}

.diagram-energy .p3::after{right:-2px;top:-8px;border-left:11px solid var(--db);border-top:6px solid transparent;border-bottom:6px solid transparent}

.diagram-energy .p4{left:18%;top:35%;height:55%;border-left:3px dashed var(--dg)}

.diagram-energy .p5{left:13%;top:88%;width:77%;border-top:3px solid #91a3ae}

.diagram-energy .p6{right:15%;top:24%;width:8px;height:58px;border-radius:4px;background:linear-gradient(to top,var(--db) 0 35%,var(--dg) 35% 67%,var(--dr) 67%)}



/* 惯性：小车向右运动，车上物体保持原运动状态。 */

.diagram-inertia .p1{left:20%;top:58%;width:58%;height:38px;border-radius:7px;background:#28769d}

.diagram-inertia .p1::before,.diagram-inertia .p1::after{bottom:-15px;width:23px;height:23px;border:4px solid #fff;border-radius:50%;background:#344e5d}.diagram-inertia .p1::before{left:10px}.diagram-inertia .p1::after{right:10px}

.diagram-inertia .p2{left:42%;top:33%;width:42px;height:45px;border:3px solid #bd773c;border-radius:6px;background:#e4a04b}

.diagram-inertia .p3{right:8%;top:48%;width:21%;border-top:5px solid var(--dr)}

.diagram-inertia .p3::after{right:-1px;top:-9px;border-left:13px solid var(--dr);border-top:7px solid transparent;border-bottom:7px solid transparent}

.diagram-inertia .p4{left:40%;top:25%;width:48px;border-top:3px dashed var(--db)}

.diagram-inertia .p5{left:13%;top:85%;width:75%;border-top:4px solid #8da0ab}

.diagram-inertia .p6{left:23%;top:52%;width:52%;border-top:3px solid rgba(255,255,255,.7)}



/* 电磁铁：线圈包围水平铁芯，两端磁极与下方电源回路一一对应。 */

.diagram-electromagnet .p1{left:18%;top:45%;width:64%;height:20px;border-radius:3px;background:#6f808a}

.diagram-electromagnet .p1::before{left:-15px;top:5px;width:15px;height:10px;border-radius:6px 0 0 6px;background:#6f808a}

.diagram-electromagnet .p2{left:29%;top:30%;width:42%;height:51px;border:5px solid #c86c3e;border-radius:16px;background:repeating-linear-gradient(90deg,transparent 0 10px,#e28b5a 10px 14px)}

.diagram-electromagnet .p3,.diagram-electromagnet .p4{top:39%;width:28px;height:28px;border:3px solid var(--dl);border-radius:50%;color:var(--dl);background:#fff;font:bold 15px Arial;text-align:center;line-height:22px}

.diagram-electromagnet .p3{left:8%}.diagram-electromagnet .p4{right:8%}.diagram-electromagnet .p3::after{content:"N";position:static}.diagram-electromagnet .p4::after{content:"S";position:static}

.diagram-electromagnet .p5{left:20%;top:74%;width:60%;height:27px;border-left:4px solid var(--db);border-right:4px solid var(--db);border-bottom:4px solid var(--db);border-radius:0 0 8px 8px}

.diagram-electromagnet .p6{left:46%;top:84%;width:25px;height:12px;border-top:3px solid var(--dr);border-bottom:7px solid var(--dr);background:var(--paper)}



/* 四冲程内燃机：气缸、活塞、连杆和曲轴飞轮形成真实传动关系。 */

.diagram-engine .p1{left:24%;top:20%;width:34%;height:99px;border:5px solid var(--dl);border-bottom:0;border-radius:7px 7px 0 0;background:#e7f2f6}

.diagram-engine .p2{left:27%;top:49%;width:28%;height:24px;border:3px solid #b87539;border-radius:4px;background:var(--dg)}

.diagram-engine .p3{left:49%;top:63%;width:39%;height:5px;border-radius:4px;background:var(--dr);transform:rotate(36deg);transform-origin:left}

.diagram-engine .p4{right:12%;bottom:10%;width:48px;height:48px;border:6px solid var(--dl);border-radius:50%;background:#fff}

.diagram-engine .p4::after{left:15px;top:15px;width:8px;height:8px;border-radius:50%;background:var(--dl)}

.diagram-engine .p5,.diagram-engine .p6{top:13%;width:5px;height:28px;background:var(--dr)}

.diagram-engine .p5{left:31%;transform:rotate(-15deg)}.diagram-engine .p6{left:48%;transform:rotate(15deg)}



/* 发电机与电动机：N、S 磁极夹住矩形线圈，线圈通过转轴连接外电路。 */

.diagram-generator .p1{left:15%;top:27%;width:70%;height:88px;border:16px solid var(--dl);border-left-width:23px;border-right-width:23px;border-radius:15px;background:transparent}

.diagram-generator .p1::before{left:-3px;top:17px;width:calc(100% + 6px);height:23px;background:#f2f8fa}

.diagram-generator .p2{left:37%;top:38%;width:26%;height:58px;border:5px solid var(--dr);background:rgba(255,255,255,.5);transform:skewY(-8deg)}

.diagram-generator .p3{left:22%;top:58%;width:56%;height:5px;border-radius:3px;background:var(--dg)}

.diagram-generator .p4,.diagram-generator .p5{top:44%;color:#fff;font:bold 16px Arial}.diagram-generator .p4{left:18%}.diagram-generator .p5{right:18%}.diagram-generator .p4::after{content:"N";position:static}.diagram-generator .p5::after{content:"S";position:static}

.diagram-generator .p6{left:45%;top:78%;width:10%;height:20px;border:4px solid var(--db);border-top:0;border-radius:0 0 7px 7px}



/* 摩擦力：物块放在粗糙水平面上，四个力从物块四周分离画出。 */

.diagram-friction .p1{left:9%;top:75%;width:82%;height:18px;border-top:5px solid var(--dl);background:repeating-linear-gradient(135deg,transparent 0 8px,rgba(34,92,120,.24) 8px 12px)}

.diagram-friction .p2{left:36%;top:42%;width:30%;height:59px;border:4px solid #9d652e;border-radius:7px;background:#e4a04b}

.diagram-friction .p3{left:66%;top:48%;width:24%;border-top:5px solid var(--dr)}

.diagram-friction .p3::after{right:-2px;top:-9px;border-left:12px solid var(--dr);border-top:7px solid transparent;border-bottom:7px solid transparent}

.diagram-friction .p4{left:12%;top:65%;width:24%;border-top:5px solid var(--db)}

.diagram-friction .p4::after{left:-2px;top:-9px;border-right:12px solid var(--db);border-top:7px solid transparent;border-bottom:7px solid transparent}

.diagram-friction .p5{left:50%;top:15%;height:27%;border-left:5px solid var(--dg)}

.diagram-friction .p5::after{left:-8px;top:-2px;border-left:8px solid transparent;border-right:8px solid transparent;border-bottom:12px solid var(--dg)}

.diagram-friction .p6{left:53%;top:66%;height:25%;border-left:5px solid var(--green)}

.diagram-friction .p6::after{left:-8px;bottom:-2px;border-left:8px solid transparent;border-right:8px solid transparent;border-top:12px solid var(--green)}



/* 声音：音叉振动推动介质形成疏密部，传播方向指向右侧听者。 */

.diagram-sound .p1{left:11%;top:20%;width:24%;height:72px;border:8px solid var(--dl);border-top:0;border-radius:0 0 24px 24px}

.diagram-sound .p1::after{left:calc(50% - 4px);top:65px;width:8px;height:41px;border-radius:4px;background:var(--dl)}

.diagram-sound .p2{left:37%;top:29%;width:39%;border-top:4px dashed var(--dr)}

.diagram-sound .p2::after{right:-2px;top:-9px;border-left:12px solid var(--dr);border-top:7px solid transparent;border-bottom:7px solid transparent}

.diagram-sound .p3{left:39%;top:44%;width:13px;height:73px;border-radius:8px;background:rgba(22,134,199,.26);box-shadow:52px 0 0 rgba(22,134,199,.2),104px 0 0 rgba(22,134,199,.26)}

.diagram-sound .p4{left:39%;top:50%;width:7px;height:7px;border-radius:50%;background:var(--db);box-shadow:15px 0 0 var(--db),30px 0 0 var(--db),45px 0 0 var(--db),60px 0 0 var(--db),75px 0 0 var(--db),90px 0 0 var(--db),105px 0 0 var(--db),120px 0 0 var(--db)}

.diagram-sound .p4::after{left:0;top:27px;width:7px;height:7px;border-radius:50%;background:var(--db);box-shadow:15px 0 0 var(--db),30px 0 0 var(--db),45px 0 0 var(--db),60px 0 0 var(--db),75px 0 0 var(--db),90px 0 0 var(--db),105px 0 0 var(--db),120px 0 0 var(--db)}

.diagram-sound .p5{right:9%;top:42%;width:35px;height:56px;border:6px solid #b56e4b;border-left-width:3px;border-radius:52% 48% 45% 55%;background:#f0bd96}

.diagram-sound .p5::after{left:8px;top:11px;width:13px;height:24px;border:4px solid #9b6046;border-left:0;border-bottom-color:transparent;border-radius:0 14px 14px 0}

.diagram-sound .p6{left:7%;top:31%;width:9px;height:36px;border:4px solid var(--dr);border-top-color:transparent;border-bottom-color:transparent;border-radius:50%}



/* 家庭电路：配电箱后的火线、零线分层布置，灯泡和三孔插座并联，保护地线单独接入插座。 */

.diagram-household .p1{left:9%;top:32%;width:51px;height:88px;border:5px solid var(--dl);border-radius:8px;background:#fff}

.diagram-household .p1::before{left:8px;top:13px;width:25px;height:25px;border:4px solid var(--dr);border-radius:5px;background:linear-gradient(90deg,transparent 42%,var(--dr) 42% 58%,transparent 58%)}

.diagram-household .p1::after{left:10px;bottom:13px;width:23px;height:8px;border-radius:4px;background:var(--dg)}

.diagram-household .p2{left:24%;top:38%;width:62%;border-top:5px solid var(--dr)}

.diagram-household .p2::before{left:34%;top:-5px;height:48px;border-left:4px solid var(--dr)}

.diagram-household .p2::after{right:12%;top:-5px;height:78px;border-left:4px solid var(--dr)}

.diagram-household .p3{left:24%;top:76%;width:62%;border-top:5px solid var(--db)}

.diagram-household .p3::before{left:34%;bottom:0;height:31px;border-left:4px solid var(--db)}

.diagram-household .p3::after{right:12%;bottom:0;height:25px;border-left:4px solid var(--db)}

.diagram-household .p4{left:51%;top:50%;width:42px;height:42px;border:5px solid #d9952b;border-radius:50%;background:#fff7d9;box-shadow:0 0 0 5px rgba(244,188,61,.13)}

.diagram-household .p4::before,.diagram-household .p4::after{left:7px;top:16px;width:20px;border-top:3px solid #d9952b;transform:rotate(45deg)}

.diagram-household .p4::after{transform:rotate(-45deg)}

.diagram-household .p5{right:7%;top:51%;width:54px;height:69px;border:5px solid var(--dl);border-radius:9px;background:radial-gradient(circle at 50% 22%,var(--dg) 0 4px,transparent 5px),radial-gradient(circle at 30% 61%,var(--db) 0 4px,transparent 5px),radial-gradient(circle at 70% 61%,var(--dr) 0 4px,transparent 5px),#fff}

.diagram-household .p6{left:23%;top:88%;width:54%;border-top:4px solid var(--green)}

.diagram-household .p6::after{right:0;bottom:0;height:20px;border-right:4px solid var(--green)}



/* 平面镜：镜面居中，物体与半透明虚像等距等大，镜后光线只用虚线表示反向延长。 */

.diagram-mirror .p1{left:49%;top:18%;width:10px;height:123px;border:3px solid #52798b;border-radius:4px;background:#c7e6ea}

.diagram-mirror .p1::after{left:7px;top:8px;width:14px;height:106px;background:repeating-linear-gradient(45deg,transparent 0 8px,#7794a1 8px 10px,transparent 10px 18px)}

.diagram-mirror .p2{left:25%;top:48%;width:30px;height:67px;border:4px solid #c84945;border-radius:7px;background:var(--dr)}

.diagram-mirror .p2::before{left:3px;top:-28px;width:16px;height:27px;border:3px solid #df713b;border-radius:60% 40% 55% 45%;background:#ffc85c}

.diagram-mirror .p2::after{right:-17px;top:25px;width:17px;height:16px;border-radius:4px;background:var(--db)}

.diagram-mirror .p3{right:25%;top:48%;width:30px;height:67px;border:4px dashed var(--dr);border-radius:7px;background:rgba(233,89,82,.12);opacity:.45}

.diagram-mirror .p3::before{left:3px;top:-28px;width:16px;height:27px;border:3px dashed #df713b;border-radius:60% 40% 55% 45%;background:rgba(255,200,92,.2)}

.diagram-mirror .p3::after{left:-17px;top:25px;width:17px;height:16px;border-radius:4px;background:rgba(20,134,199,.45)}

.diagram-mirror .p4{left:31%;top:35%;width:18%;border-top:4px solid #e89e32;transform:rotate(18deg);transform-origin:right}

.diagram-mirror .p4::after{right:-2px;top:-8px;width:11px;height:11px;border:3px solid #e56d42;border-radius:50%;background:#fff}

.diagram-mirror .p5{left:50%;top:43%;width:22%;border-top:3px dashed #7694a2;transform:rotate(-15deg);transform-origin:left}

.diagram-mirror .p5::after{left:0;top:22px;width:100%;border-top:3px dashed #7694a2;transform:rotate(15deg);transform-origin:left}

.diagram-mirror .p6{left:25%;top:88%;width:50%;border-top:3px solid #6c8997}

.diagram-mirror .p6::before,.diagram-mirror .p6::after{top:-7px;height:14px;border-left:3px solid #6c8997}.diagram-mirror .p6::before{left:0}.diagram-mirror .p6::after{right:0}



/* 首页直接使用模型真实实验画面，避免手绘缩略图出现光路、绕绳或器材结构错误。 */

.thumbnail-diagram{

  background-position:center;

  background-repeat:no-repeat;

  background-size:cover;

  filter:saturate(.96) contrast(1.02);

  transform:scale(1.002);

  transition:transform .25s ease;

}

.thumbnail-diagram::after{

  position:absolute;

  z-index:1;

  inset:0;

  content:"";

  background:linear-gradient(180deg,rgba(12,40,53,.14),transparent 34%,transparent 73%,rgba(12,40,53,.08));

  pointer-events:none;

}

.thumbnail-diagram .part{display:none}

.model-card:not(.locked):hover .thumbnail-diagram{transform:scale(1.025)}

.diagram-pump{background-image:var(--thumbnail-load,url("/static/model-thumbnails/pump.jpg"))}

.diagram-lens{background-image:var(--thumbnail-load,url("/static/model-thumbnails/lens.jpg"))}

.diagram-ray{background-image:var(--thumbnail-load,url("/static/model-thumbnails/ray.jpg"))}

.diagram-resistor{background-image:var(--thumbnail-load,url("/static/model-thumbnails/resistor.jpg"))}

.diagram-circuit{background-image:var(--thumbnail-load,url("/static/model-thumbnails/circuit.jpg"))}

.diagram-lever{background-image:var(--thumbnail-load,url("/static/model-thumbnails/lever.jpg"))}

.diagram-float{background-image:var(--thumbnail-load,url("/static/model-thumbnails/float.jpg"))}

.diagram-pressure{background-image:var(--thumbnail-load,url("/static/model-thumbnails/liquid-pressure.png?v=liquid-3d-20260923"))}

.diagram-thermo{background-image:var(--thumbnail-load,url("/static/model-thumbnails/thermo.jpg"))}

.diagram-atmosphere{background-image:var(--thumbnail-load,url("/static/model-thumbnails/atmosphere.jpg?v=atmosphere-3d-20260923"))}

.diagram-incline{background-image:var(--thumbnail-load,url("/static/model-thumbnails/incline.jpg?v=56a7b969201f"))}

.diagram-pulley{background-image:var(--thumbnail-load,url("/static/model-thumbnails/pulley.jpg?v=2845499e799c"))}

.diagram-energy{background-image:var(--thumbnail-load,url("/static/model-thumbnails/energy.jpg"))}

.diagram-inertia{background-image:var(--thumbnail-load,url("/static/model-thumbnails/inertia.jpg?v=inertia-3d-20260923"))}

.diagram-electromagnet{background-image:var(--thumbnail-load,url("/static/model-thumbnails/electromagnet.jpg"))}

.diagram-engine{background-image:var(--thumbnail-load,url("/static/model-thumbnails/engine.jpg"))}

.diagram-generator{background-image:var(--thumbnail-load,url("/static/model-thumbnails/generator.png"))}

.diagram-friction{background-image:var(--thumbnail-load,url("/static/model-thumbnails/friction.jpg"))}





.diagram-mirror{background-image:var(--thumbnail-load,url("/static/model-thumbnails/mirror.jpg"))}



























.diagram-projectile{background-image:var(--thumbnail-load,url("/static/model-thumbnails/projectile-motion.png"))}

.diagram-centripetal{background-image:var(--thumbnail-load,url("/static/model-thumbnails/circular-motion.svg"))}

.diagram-newton2{background-image:var(--thumbnail-load,url("/static/model-thumbnails/newton-second-law.svg"))}

.diagram-conveyor{background-image:var(--thumbnail-load,url("/static/model-thumbnails/conveyor-belt.svg"))}



.diagram-spring-oscillator{background-image:var(--thumbnail-load,url("/static/model-thumbnails/spring-oscillator.svg"))}

.diagram-satellite-transfer{background-image:var(--thumbnail-load,url("/static/model-thumbnails/satellite-orbit-transfer.svg"))}

















.diagram-double-slit{background-image:var(--thumbnail-load,url("/static/model-thumbnails/double-slit-interference.svg"))}

















.diagram-microscope-imaging{background-image:var(--thumbnail-load,url("/static/model-thumbnails/microscope-use-imaging.svg"))}

.diagram-animal-plant-cell{background-image:var(--thumbnail-load,url("/static/model-thumbnails/animal-plant-cell.svg"))}

.diagram-cell-development{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cell-division-growth-differentiation.svg"))}

.diagram-photo-respiration{background-image:var(--thumbnail-load,url("/static/model-thumbnails/photosynthesis-respiration-comparison.svg"))}





.diagram-heart-circulation{background-image:var(--thumbnail-load,url("/static/model-thumbnails/heart-blood-circulation.svg"))}





.diagram-root-transpiration{background-image:var(--thumbnail-load,url("/static/model-thumbnails/root-water-transpiration.svg"))}

.diagram-reference-frame{background-image:var(--thumbnail-load,url("/static/model-thumbnails/reference-frame.svg"))}

.diagram-route-displacement{background-image:var(--thumbnail-load,url("/static/model-thumbnails/route-position-displacement.svg"))}

.diagram-position-time-graph{background-image:var(--thumbnail-load,url("/static/model-thumbnails/position-time-graph.svg?v=20260908-redraw2"))}

.diagram-average-speed{background-image:var(--thumbnail-load,url("/static/model-thumbnails/average-instantaneous-speed.svg"))}

.diagram-pursuit-encounter{background-image:var(--thumbnail-load,url("/static/model-thumbnails/pursuit-encounter.svg"))}
.diagram-chapter2-motion-review{background-image:var(--thumbnail-load,url("/static/model-thumbnails/chapter2-motion-review.svg"))}
.diagram-ticker-timer{background-image:var(--thumbnail-load,url("/static/model-thumbnails/ticker-timer.svg"))}

.diagram-average-speed-velocity{background-image:var(--thumbnail-load,url("/static/model-thumbnails/average-speed-velocity.svg"))}

.diagram-speed-direction-sign{background-image:var(--thumbnail-load,url("/static/model-thumbnails/speed-direction-sign.svg?v=20260908g"))}

.diagram-car-speed-interval{background-image:var(--thumbnail-load,url("/static/model-thumbnails/car-speed-interval.svg?v=20260909c"))}

.diagram-same-average-motion{background-image:var(--thumbnail-load,url("/static/model-thumbnails/same-average-motion.svg"))}

.diagram-acceleration-three-link{background-image:var(--thumbnail-load,url("/static/model-thumbnails/acceleration-three-link.svg"))}

.diagram-vt-slope-acceleration{background-image:var(--thumbnail-load,url("/static/model-thumbnails/vt-slope-acceleration.svg?v=20260906E"))}

.diagram-strobe-acceleration{background-image:var(--thumbnail-load,url("/static/model-thumbnails/strobe-acceleration.svg"))}

.diagram-uniform-acceleration{background-image:var(--thumbnail-load,url("/static/model-thumbnails/uniform-acceleration-characteristics.svg"))}

.diagram-ruler-reaction-time{background-image:var(--thumbnail-load,url("/static/model-thumbnails/ruler-reaction-time.svg?v=20261009-redraw"))}

.diagram-uniform-acceleration-laws{background-image:var(--thumbnail-load,url("/static/model-thumbnails/uniform-acceleration-laws.svg?v=20260912-derivation"))}

.diagram-car-braking-distance{background-image:var(--thumbnail-load,url("/static/model-thumbnails/car-braking-distance.svg"))}

.diagram-free-fall-gravity{background-image:var(--thumbnail-load,url("/static/model-thumbnails/free-fall-gravity.svg"))}



/* 未登录卡片不遮挡原理图；登录提示收纳到卡片底部操作区。 */

.model-card.locked .lock-layer{inset:auto 14px 14px;height:52px;display:flex;align-items:center;justify-content:flex-start;flex-direction:row;gap:8px;padding:8px 9px;border:1px solid #cfe0e8;border-radius:10px;background:#f2f8fa;box-shadow:0 7px 18px rgba(28,63,89,.08)}

.model-card.locked .lock-layer>span{width:30px;height:30px;border-radius:8px;font-size:12px;transform:none}

.model-card.locked .lock-layer b{margin:0;font-size:12px}

.model-card.locked .lock-layer a{margin-left:auto;padding:7px 10px}



/* 学习额度、会员中心和新增卡片状态。 */

.credit-badge,.member-badge{position:absolute;z-index:3;right:13px;bottom:11px;padding:5px 8px;border-radius:6px;color:#fff;font-size:10px;font-style:normal;font-weight:900}

.credit-badge{background:#b77922}

.member-badge{background:#7755a7}

.gallery-head .quota-empty{color:#8c4a43;background:#ffebe8}

.gallery-head .quota-empty a{color:var(--red);font-weight:900}

.account-page{grid-template-columns:minmax(260px,340px) minmax(360px,460px);gap:22px}

.account-summary{align-self:stretch;padding:34px;border:1px solid #cde0ea;border-radius:18px;color:#fff;background:linear-gradient(145deg,#165478,#168b8b);box-shadow:0 16px 42px rgba(25,60,85,.12)}

.account-summary>p{margin:0 0 18px;color:#ccecf1;font-size:11px;font-weight:900;letter-spacing:.16em}

.account-summary h1{margin:0;font-size:32px}

.account-plan{display:grid;gap:5px;margin:30px 0;padding:19px;border:1px solid rgba(255,255,255,.2);border-radius:13px;background:rgba(255,255,255,.1)}

.account-plan b{font-size:23px}

.account-plan span{color:#d7f3f1;font-size:13px}

.account-summary>a{display:inline-block;padding:10px 13px;border-radius:8px;color:#165478;background:#fff;font-size:13px;font-weight:900}

.membership-heading{padding-bottom:20px}

.membership-layout{display:grid;grid-template-columns:minmax(290px,.75fr) minmax(420px,1.25fr);gap:18px}

.membership-status,.membership-offer{padding:32px;border:1px solid var(--line);border-radius:18px;background:#fff;box-shadow:0 14px 35px rgba(28,63,89,.07)}

.membership-status>span,.offer-label{color:var(--green);font-size:11px;font-weight:900;letter-spacing:.15em}

.membership-status h2,.membership-offer h2{margin:7px 0 16px;font-size:30px}

.membership-status>p,.membership-offer>p{color:#687d8e;line-height:1.75}

.status-chip{width:max-content;padding:10px 13px;border-radius:9px;font-size:13px;font-weight:900}

.status-chip.permanent{color:#6b4a91;background:#efe7fa}

.quota-number{display:flex;align-items:end;gap:10px;margin:24px 0 15px}

.quota-number b{color:var(--blue);font:900 72px Georgia,serif;line-height:.85}

.quota-number span{color:#687d8e;font-weight:800}

.membership-offer{position:relative;overflow:hidden;border-color:#c8dce8}

.membership-offer::after{position:absolute;right:-58px;top:-58px;width:170px;height:170px;border:28px solid rgba(22,134,199,.07);border-radius:50%;content:""}

.offer-price{position:relative;z-index:1;display:flex;align-items:baseline;gap:13px;margin:20px 0}

.offer-price del{color:#91a1ac;font-size:18px}

.offer-price b{color:var(--red);font-size:48px;letter-spacing:-.04em}

.membership-offer ul{display:grid;gap:10px;margin:0 0 22px;padding:0;list-style:none}

.membership-offer li{color:#526d7f;font-size:14px;font-weight:700}

.membership-offer li::before{margin-right:9px;color:var(--green);content:"✓"}

.promo-form label{display:grid;gap:7px;color:#536a7c;font-size:12px;font-weight:900}

.promo-form label>span{display:grid;grid-template-columns:1fr auto;gap:8px}

.promo-form input{height:44px;padding:0 12px;border:1px solid #cbd9e3;border-radius:8px;outline:0;text-transform:uppercase}

.promo-form button,.promo-create-form>button{padding:0 17px;border:0;border-radius:8px;color:#fff;background:var(--blue);font-weight:900}

.manual-contact{position:relative;z-index:1;margin-top:18px;padding:18px;border:1px solid #f2c7cd;border-radius:14px;background:linear-gradient(145deg,#fff7f8,#fff)}

.manual-contact-head{display:flex;align-items:center;gap:12px;margin-bottom:16px}

.manual-contact-head>span{flex:0 0 auto;padding:7px 10px;border-radius:7px;color:#fff;background:#ff2442;font-size:12px;font-weight:900}

.manual-contact-head>div{display:grid;gap:3px}

.manual-contact-head strong{font-size:19px}

.manual-contact-head small{color:#758895;font-size:12px;line-height:1.5}

.manual-contact-grid{display:grid;grid-template-columns:260px minmax(0,1fr);align-items:start;gap:18px}

.xiaohongshu-card{margin:0;padding:8px;border:1px solid #e5eaed;border-radius:12px;background:#fff;box-shadow:0 8px 22px rgba(35,61,78,.09)}

.xiaohongshu-qr-window{position:relative;overflow:hidden;width:100%;aspect-ratio:1;border-radius:8px;background:#fff}

/* 无损放大原名片右下角二维码：只改变显示窗口，不重绘或修改二维码点阵。 */

.xiaohongshu-qr-window img{position:absolute;left:-240.74%;top:-374.07%;width:365.56%;max-width:none;height:auto;display:block}

.xiaohongshu-card figcaption{margin-top:8px;color:#768a98;text-align:center;font-size:11px;font-weight:700}

.manual-contact-guide{display:grid;gap:12px}

.contact-price{display:flex;align-items:baseline;justify-content:space-between;padding:10px 12px;border-radius:9px;background:#fff0f2}

.contact-price span{color:#754f57;font-size:12px;font-weight:800}

.contact-price b{color:#d9364e;font-size:25px}

.manual-contact-guide ol{display:grid;gap:12px;margin:0;padding:0;counter-reset:contact-step;list-style:none}

.manual-contact-guide li{position:relative;display:grid;gap:2px;min-height:34px;padding-left:42px;counter-increment:contact-step}

.manual-contact-guide li::before{position:absolute;left:0;top:0;width:30px;height:30px;display:grid;place-items:center;border-radius:50%;color:#fff;background:#2b6e8f;content:counter(contact-step);font-size:13px;font-weight:900}

.manual-contact-guide li b{color:#294f65;font-size:14px}

.manual-contact-guide li span{color:#708391;font-size:12px;line-height:1.55}

.manual-contact-guide li span strong{color:var(--blue);font-size:14px}

.contact-security{margin:0;padding:10px 12px;border-left:4px solid #e2a038;border-radius:7px;color:#765d32;background:#fff7e7;font-size:12px;font-weight:700;line-height:1.65}

.already-open{margin-top:26px;padding:16px;border-radius:10px;color:#176f5d;background:#e5f6f0;font-weight:900}



/* 管理员会员、优惠码与订单操作。 */

.member-admin-list{display:grid;gap:9px}

.member-admin-card{display:grid;grid-template-columns:minmax(150px,1fr) 150px minmax(220px,auto) minmax(250px,1fr);align-items:center;gap:12px;padding:13px;border:1px solid var(--line);border-radius:10px}

.member-admin-identity{display:grid}

.member-admin-identity small{color:#8496a3;font-size:11px}

.member-admin-state{display:flex;align-items:center;justify-content:space-between;gap:8px}

.member-admin-state strong{color:var(--blue)}

.member-admin-actions{display:flex;gap:7px;min-width:230px}

.member-admin-actions form{flex:1}

.member-admin-actions button{width:100%;height:38px;white-space:nowrap}

.member-button,.soft-button,.soft-danger,.reset-password-form button,.promo-list button{padding:0 10px;border:1px solid transparent;border-radius:7px;font-weight:800}

.member-button{color:#fff;background:var(--green)}

.soft-button{color:#25627f;border-color:#cbdce6;background:#edf5f8}

.soft-danger{color:#a74740;border-color:#f0c7c3;background:#fff0ee}

.reset-password-form{display:grid;grid-template-columns:1fr auto;gap:7px}

.reset-password-form input{height:38px;min-width:0;padding:0 10px;border:1px solid #cbd9e3;border-radius:7px}

.reset-password-form button{color:#fff;background:var(--blue)}

.promo-create-form{display:grid;grid-template-columns:1fr 1fr 1fr auto;align-items:end;gap:10px;margin-bottom:13px;padding:14px;border-radius:10px;background:#f1f7fa}

.promo-create-form label{display:grid;gap:5px;color:#526b7c;font-size:11px;font-weight:900}

.promo-create-form input{height:40px;padding:0 10px;border:1px solid #cad9e2;border-radius:7px}

.promo-create-form>button{height:40px}

.promo-list,.order-list{overflow:hidden;border:1px solid var(--line);border-radius:10px}

.promo-list>div,.order-list>div{display:grid;grid-template-columns:1fr .55fr .8fr 1fr auto;align-items:center;gap:10px;padding:11px 13px;border-top:1px solid var(--line);font-size:12px}

.promo-list>div:first-child,.order-list>div:first-child{border-top:0}

.promo-list span,.order-list span,.order-list time{color:#6e8291}

.order-list strong{color:var(--blue)}



/* 模型使用漏斗：突出独立人数与操作转化，同时保留按模型明细。 */

.analytics-heading{align-items:center}

.analytics-periods{display:flex;gap:5px;padding:4px;border-radius:10px;background:#edf4f7}

.analytics-periods a{padding:7px 11px;border-radius:7px;color:#607887;font-size:12px;font-weight:900}

.analytics-periods a.active{color:#fff;background:var(--blue);box-shadow:0 4px 10px rgba(26,91,125,.2)}

.analytics-note{margin:-3px 0 14px;color:#718795;font-size:12px}

.analytics-cards{display:grid;grid-template-columns:repeat(4,1fr);gap:10px;margin-bottom:13px}

.analytics-cards article{display:grid;gap:3px;min-height:118px;padding:17px;border:1px solid #d8e6ec;border-radius:12px;background:linear-gradient(145deg,#f8fbfc,#edf6f8)}

.analytics-cards article.highlight{border-color:#bce0d3;background:linear-gradient(145deg,#f4fbf8,#e5f5ef)}

.analytics-cards article.locked-metric{border-color:#efdbc0;background:linear-gradient(145deg,#fffaf2,#fff1dc)}

.analytics-cards span{color:#607887;font-size:12px;font-weight:900}

.analytics-cards b{color:#173f57;font-size:34px;line-height:1.1}

.analytics-cards small{color:#7a8f9b;font-size:11px;line-height:1.45}

.model-analytics-table{overflow-x:auto;border:1px solid var(--line);border-radius:10px}

.model-analytics-head,.model-analytics-row{display:grid;grid-template-columns:minmax(200px,1.7fr) .65fr .65fr .65fr .65fr 1fr;align-items:center;gap:10px;min-width:780px;padding:10px 13px}

.model-analytics-head{color:#6b8091;background:#eef5f8;font-size:11px;font-weight:900}

.model-analytics-row{border-top:1px solid var(--line);font-size:12px}

.model-analytics-row b{color:#284f68}.model-analytics-row strong{color:var(--blue);font-size:17px}

.model-analytics-row span,.model-analytics-row time{color:#718794}.model-analytics-row time{font-size:11px}



/* 首页学科分组：标签只筛选卡片，不改变原始顺序及访问权限。 */

.model-groups{margin:-2px 0 22px;padding:15px;border:1px solid var(--line);border-radius:16px;background:#fff;box-shadow:0 8px 24px rgba(28,63,89,.045)}

.model-group-intro{display:flex;align-items:end;justify-content:space-between;gap:16px;margin:0 2px 12px}

.model-group-intro span{color:var(--green);font-size:11px;font-weight:900;letter-spacing:.14em}

.model-group-intro h3{margin:3px 0 0;font-size:22px}

.model-group-intro p{margin:0;color:#6c8292;font-size:13px;font-weight:800}

.model-group-tabs{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:9px}

.model-group-tab{min-height:50px;display:flex;align-items:center;justify-content:space-between;gap:8px;padding:9px 12px;border:1px solid #d5e2e9;border-radius:11px;color:#46677c;background:#f8fbfc;font-weight:900;transition:.18s ease}

.model-group-tab:hover{border-color:#93c8dc;background:#f1f9fb}

.model-group-tab b{min-width:28px;padding:4px 7px;border-radius:7px;color:#53788d;background:#e5f0f5;font-size:12px}

.model-group-tab.active{border-color:#1686c7;color:#fff;background:linear-gradient(135deg,#1686c7,#168c8a);box-shadow:0 8px 18px rgba(22,134,199,.18)}

.model-group-tab.active b{color:#176478;background:rgba(255,255,255,.88)}

.model-card-link[hidden],.model-card[hidden]{display:none!important}



@media(max-width:1100px){

  .member-admin-card{grid-template-columns:1fr 150px}

  .promo-create-form{grid-template-columns:1fr 1fr}

  .analytics-cards{grid-template-columns:1fr 1fr}

}

@media(max-width:760px){

  .account-page,.membership-layout{grid-template-columns:1fr}

  .account-page{padding-top:24px}

  .member-admin-card{grid-template-columns:1fr}

  .promo-create-form{grid-template-columns:1fr}

  .promo-create-form>button{height:44px}

  .promo-list>div,.order-list>div{grid-template-columns:1fr 1fr}

  .promo-list form{justify-self:end}

  .membership-status,.membership-offer{padding:24px 20px}

  .manual-contact-grid{grid-template-columns:230px minmax(0,1fr)}

}

@media(max-width:900px){

  .model-group-tabs{grid-template-columns:repeat(3,minmax(0,1fr))}

}

@media(max-width:900px){

  .site-header nav .nav-login,.site-header nav .nav-member{display:inline-flex!important}

}

.nav-mobile-auth{display:none}

@media(max-width:600px){

  .site-header nav .nav-login,.site-header nav .nav-cta{display:none!important}

  .site-header nav .nav-mobile-auth{display:inline-flex!important}

  .manual-contact{padding:15px}

  .manual-contact-grid{grid-template-columns:1fr}

  .xiaohongshu-card{width:min(300px,100%);justify-self:center}

  .analytics-heading{align-items:flex-start;flex-direction:column}

  .analytics-cards{grid-template-columns:1fr 1fr}

  .analytics-cards article{min-height:104px;padding:13px}

  .analytics-cards b{font-size:29px}

  .model-groups{padding:12px}

  .model-group-intro{align-items:flex-start}

  .model-group-tabs{grid-template-columns:repeat(2,minmax(0,1fr))}

  .model-group-tab{min-height:47px;padding:8px 10px;font-size:13px}

  .model-group-tab:first-child{grid-column:1/-1}

}



/* 全站免费阶段：首页先讲清价值，再让访客一键进入模型。 */

.free-hero{min-height:430px;margin:24px 0 28px;padding:52px 44px;border:1px solid #d5e7ee;border-radius:26px;background:radial-gradient(circle at 76% 12%,rgba(116,220,201,.2),transparent 27%),linear-gradient(145deg,#fafdff 0%,#eef8fa 100%);box-shadow:0 20px 55px rgba(29,76,101,.08)}

.free-hero .eyebrow{display:flex;align-items:center;gap:8px;color:#147c69}

.free-live-dot{width:9px;height:9px;border-radius:50%;background:#21a67f;box-shadow:0 0 0 6px rgba(33,166,127,.12);animation:freePulse 1.8s ease-in-out infinite}

@keyframes freePulse{50%{box-shadow:0 0 0 10px rgba(33,166,127,0)}}

.hero-actions{display:flex;align-items:center;gap:16px;margin-top:25px}

.hero-primary{display:inline-flex;align-items:center;gap:24px;padding:13px 18px;border-radius:11px;color:#fff;background:linear-gradient(135deg,#1686c7,#168c73);box-shadow:0 10px 24px rgba(22,134,169,.22);font-size:15px;font-weight:900;transition:.18s ease}

.hero-primary:hover{transform:translateY(-2px);box-shadow:0 14px 30px rgba(22,134,169,.28)}

.hero-primary i{font-size:20px;font-style:normal}.hero-actions>span{color:#6b8190;font-size:13px;font-weight:800}

.hero-benefits{display:flex;flex-wrap:wrap;gap:9px;margin:20px 0 0;padding:0;list-style:none}

.hero-benefits li{padding:7px 10px;border:1px solid #d2e5e7;border-radius:999px;color:#376b75;background:rgba(255,255,255,.74);font-size:12px;font-weight:900}

.hero-benefits li::before{margin-right:6px;color:#168c73;content:"✓"}

.free-hero .hero-panel{padding:30px}.free-hero .hero-panel>b{margin-top:4px}

.hero-subjects{position:relative;z-index:2;display:grid;grid-template-columns:1fr 1fr;gap:7px;margin-top:20px}

.hero-subjects span{padding:7px 8px;border:1px solid rgba(255,255,255,.18);border-radius:8px;color:#e8fbf8;background:rgba(255,255,255,.09);font-size:11px;font-weight:800}

.free-open-banner{display:flex;align-items:center;justify-content:space-between;gap:20px;margin-bottom:25px;padding:14px 18px;border:1px solid #bfe5d8;border-radius:14px;color:#245f53;background:linear-gradient(90deg,#e5f7f0,#f1fbf7)}

.free-open-banner>div{display:flex;align-items:center;gap:12px}.free-open-banner strong{padding:6px 9px;border-radius:7px;color:#fff;background:#168c73;font-size:12px}.free-open-banner span{font-size:14px;font-weight:800}.free-open-banner>a{color:#0874a8;font-size:13px;font-weight:900}

.model-card:not(.locked):hover{border-color:#abd6df}.free-badge{background:linear-gradient(135deg,#168c73,#27a77f);box-shadow:0 5px 12px rgba(22,140,115,.2)}

.free-access-layout{grid-template-columns:minmax(290px,.82fr) minmax(420px,1.18fr)}

.free-access-link{display:inline-flex;margin-top:18px;padding:11px 14px;border-radius:9px;color:#fff;background:var(--blue);font-size:13px;font-weight:900}

.free-follow-card{border-color:#c8e5dc;background:linear-gradient(145deg,#fff,#f2fbf7)}

.free-access-points{display:flex;flex-wrap:wrap;gap:8px;margin:20px 0}.free-access-points span{padding:7px 10px;border-radius:999px;color:#176f5d;background:#e3f5ee;font-size:12px;font-weight:900}

.free-follow-row{display:grid;grid-template-columns:150px 1fr;align-items:center;gap:20px;margin-top:18px}.free-follow-row .xiaohongshu-qr-window{width:150px;height:150px}.free-follow-row>div:last-child{display:grid;gap:8px}.free-follow-row b{font-size:18px}.free-follow-row span{color:#526d7f;font-size:14px;line-height:1.6}.free-follow-row small{color:#7d929f}

@media(max-width:900px){.free-hero{margin-top:14px;padding:44px 28px}.free-access-layout{grid-template-columns:1fr}}

@media(max-width:600px){

  .free-hero{min-height:auto;margin:10px 0 20px;padding:34px 18px;border-radius:19px}

  .free-hero h1{font-size:39px}.hero-actions{align-items:flex-start;flex-direction:column;gap:10px}

  .hero-primary{width:100%;justify-content:space-between}.free-open-banner{align-items:flex-start;flex-direction:column;gap:10px}

  .free-open-banner>div{align-items:flex-start;flex-direction:column;gap:7px}

  .free-follow-row{grid-template-columns:110px 1fr;gap:14px}.free-follow-row .xiaohongshu-qr-window{width:110px;height:110px}

}



.diagram-acceleration-vt{background-image:var(--thumbnail-load,url("/static/model-thumbnails/acceleration-direction-vt.svg"))}



.diagram-particle-judgment{background-image:var(--thumbnail-load,url("/static/model-thumbnails/particle-judgment.svg"))}

.diagram-photogate-speed{background-image:var(--thumbnail-load,url("/static/model-thumbnails/photogate-speed.svg"))}

.diagram-beidou-positioning{background-image:var(--thumbnail-load,url("/static/model-thumbnails/beidou-positioning.svg"))}



/* 20260906 教师工作台首页：价值优先、模型分层，弱化“免费资源库”气质。 */

.professional-hero{position:relative;overflow:hidden;background:radial-gradient(circle at 83% 18%,rgba(71,178,168,.22),transparent 24%),linear-gradient(135deg,#fafdff 0%,#edf7fb 58%,#e8f5f0 100%)}

.professional-hero::after{position:absolute;right:4%;bottom:-70px;width:310px;height:310px;border:1px solid #acd9d5;border-radius:50%;box-shadow:0 0 0 28px #acd9d52e,0 0 0 58px #acd9d51c;content:"";pointer-events:none}.professional-hero .hero-main{position:relative;z-index:1}.professional-hero h1{font-size:52px;letter-spacing:-.04em}.professional-hero h1 em{color:#137c73;font-style:normal}.professional-hero .hero-copy{max-width:600px;font-size:18px;line-height:1.8}.professional-hero .hero-panel{position:relative;z-index:1;border:1px solid #c4e0df;border-radius:18px;background:linear-gradient(160deg,#195875,#126c6b);box-shadow:0 18px 38px #18516a2b}.professional-hero .hero-panel>b{font-size:76px}.professional-banner{border-color:#c9dfeb;color:#285871;background:linear-gradient(90deg,#eef8fc,#f4fbfa)}.professional-banner strong{color:#fff;background:#266c8c}.professional-banner>a{color:#0b718f}.featured-section{margin:8px 0 30px}.section-kicker{margin-bottom:7px;color:#148174;font-size:12px;font-weight:900;letter-spacing:.16em}.featured-heading-row{display:flex;align-items:end;justify-content:space-between;gap:20px;margin-bottom:15px}.featured-heading-row h2{margin:0 0 5px;font-size:29px}.featured-heading-row p{margin:0;color:#6b8091;font-size:14px}.featured-heading-row>a{padding-bottom:4px;color:#0874a8;font-size:13px;font-weight:900}.featured-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}.featured-card{display:grid;grid-template-columns:90px 1fr;align-items:center;gap:14px;min-height:142px;padding:15px;border:1px solid #d4e4e8;border-radius:15px;color:inherit;background:#fff;box-shadow:0 8px 22px #1c3f590b;transition:.2s ease}.featured-card:hover{transform:translateY(-3px);border-color:#9bcfd4;box-shadow:0 14px 30px #1c3f591a}.featured-icon{position:relative;height:94px;overflow:hidden;border-radius:12px;background:linear-gradient(145deg,#eaf7fb,#f5fbf8);background-size:cover;background-position:center}.featured-card>div:last-child>span{color:#6b8091;font-size:11px;font-weight:800}.featured-card h3{margin:5px 0;font-size:17px}.featured-card p{display:-webkit-box;overflow:hidden;margin:0;color:#718596;font-size:12px;line-height:1.5;-webkit-box-orient:vertical;-webkit-line-clamp:2}.featured-card b{display:block;margin-top:10px;color:#0874a8;font-size:12px}.featured-icon .part{position:absolute;display:block}.featured-icon .p1{left:16%;top:53%;width:68%;height:9px;border-radius:8px;background:#258aaa}.featured-icon .p2{left:34%;top:31%;width:28%;height:28%;border:4px solid #ef855c;border-radius:50%}.featured-icon .p3{left:48%;top:14%;width:5px;height:70%;background:#efc45e}.featured-icon.diagram-reaction .p1{left:17%;top:48%;width:25%;height:25%;border-radius:50%;background:#55b89a}.featured-icon.diagram-reaction .p2{left:59%;top:28%;width:25%;height:25%;border-radius:50%;background:#ef8763}.featured-icon.diagram-circuit .p1{left:20%;top:22%;width:60%;height:54%;border:4px solid #4292b4;border-radius:10px;background:transparent}.featured-icon.diagram-circuit .p2{left:45%;top:28%;width:12%;height:42%;border-radius:5px;background:#ef8763}.featured-icon.diagram-float .p1{left:20%;top:50%;width:60%;height:28%;border-radius:6px 6px 22px 22px;background:#55a9c2}.featured-icon.diagram-float .p2{left:39%;top:31%;width:22%;height:27%;border-radius:50%;background:#f09361}.featured-icon.diagram-lens .p1{left:43%;top:12%;width:14%;height:76%;border:3px solid #3c9abc;border-radius:50%;background:#d5f2f5}.featured-icon.diagram-lens .p2{left:20%;top:50%;width:60%;height:3px;background:#e68b61}

@media(max-width:900px){.professional-hero h1{font-size:45px}.featured-grid{grid-template-columns:repeat(2,1fr)}.featured-card:last-child{display:none}}

@media(max-width:600px){.professional-hero h1{font-size:39px}.professional-hero .hero-copy{font-size:15px}.featured-heading-row{align-items:flex-start;flex-direction:column;gap:7px}.featured-grid{grid-template-columns:1fr}.featured-card:last-child{display:grid}.featured-card{min-height:126px}.featured-icon{height:82px}.gallery-head h2{font-size:25px}}



/* 20260831 课件中心 */

.nav-lessons{padding:8px 12px;border-radius:9px;color:#0c739f!important;background:#eaf7fc}

.hero-lesson-link{display:inline-flex;align-items:center;gap:18px;padding:12px 17px;border:1px solid #b9d7e5;border-radius:11px;color:#236681;background:#fff;font-size:14px;font-weight:900;transition:.18s ease}

.hero-lesson-link:hover{transform:translateY(-2px);border-color:#65acce;box-shadow:0 10px 24px #1686c71b}

.hero-lesson-link i{font-size:18px;font-style:normal}

/* 课件中心：面向课堂使用的资源工作台，首屏直接呈现筛选、课件和授课流程。 */

.lesson-hub{padding:34px 0 76px}

.lesson-hub-header{display:flex;align-items:flex-end;justify-content:space-between;gap:44px;padding:6px 2px 30px;border-bottom:1px solid var(--line)}

.lesson-hub-heading>a,.lesson-hub-heading>span,.lesson-hub-heading>b{font-size:12px;font-weight:900}.lesson-hub-heading>a{color:var(--blue)}.lesson-hub-heading>span{margin:0 8px;color:#9aabb6}.lesson-hub-heading>b{color:#657c8c}

.lesson-hub-heading h1{margin:16px 0 9px;font-size:clamp(34px,4vw,52px);line-height:1.08;letter-spacing:-.045em}.lesson-hub-heading p{max-width:760px;margin:0;color:#657b8b;font-size:16px;line-height:1.7}

.lesson-hub-summary{display:grid;grid-template-columns:repeat(3,96px);margin:0;padding:0}.lesson-hub-summary>div{padding:3px 18px;border-left:1px solid var(--line)}.lesson-hub-summary dt{color:var(--ink);font:900 31px/1 Georgia,serif}.lesson-hub-summary dd{margin:7px 0 0;color:#748897;font-size:11px;font-weight:900}

.lesson-toolbar{display:flex;align-items:center;justify-content:space-between;gap:24px;margin:22px 0 30px;padding:11px 12px;border:1px solid var(--line);background:#fff;box-shadow:0 8px 24px rgba(28,63,89,.045)}

.lesson-filter-group{display:flex;align-items:center;gap:6px}.lesson-filter-group button{height:39px;padding:0 14px;border:0;color:#617789;background:transparent;font-size:13px;font-weight:900}.lesson-filter-group button span{margin-left:5px;color:#97a7b2}.lesson-filter-group button.is-active{color:#fff;background:var(--ink)}.lesson-filter-group button.is-active span{color:#bcd2df}

.lesson-search{width:min(340px,100%);height:39px;display:flex;align-items:center;gap:9px;padding:0 12px;border:1px solid #d3e0e7;background:#f8fbfc}.lesson-search>span{color:var(--blue);font:900 22px/1 Georgia,serif}.lesson-search input{width:100%;border:0;outline:0;color:var(--ink);background:transparent;font-size:13px}.lesson-search input::placeholder{color:#8da0ad}

.lesson-workspace{display:grid;grid-template-columns:minmax(0,1fr) 310px;align-items:start;gap:30px}.lesson-library{min-width:0}.lesson-section-heading{display:flex;align-items:flex-end;justify-content:space-between;margin:0 0 14px}.lesson-section-heading span{color:var(--green);font-size:10px;font-weight:900;letter-spacing:.16em}.lesson-section-heading h2{margin:5px 0 0;font-size:25px}.lesson-section-heading p{margin:0;color:#7a8d9a;font-size:12px}.lesson-section-heading p b{color:var(--ink);font-size:18px}

.lesson-card-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:18px}.lesson-card{overflow:hidden;border:1px solid #d8e4eb;background:#fff;box-shadow:0 10px 28px rgba(28,63,89,.055);transition:transform .18s ease,box-shadow .18s ease}.lesson-card:hover{transform:translateY(-3px);box-shadow:0 18px 38px rgba(28,63,89,.11)}.lesson-card[hidden]{display:none}

.lesson-cover{position:relative;display:block;aspect-ratio:16/8.6;overflow:hidden;background:#eaf3f7}.lesson-cover img{width:100%;height:100%;display:block;object-fit:cover;transition:transform .28s ease}.lesson-card:hover .lesson-cover img{transform:scale(1.018)}.lesson-cover-grade{position:absolute;top:14px;left:14px;padding:7px 10px;color:#fff;background:rgba(20,57,78,.88);font-size:11px;font-weight:900;backdrop-filter:blur(8px)}.lesson-cover-play{position:absolute;right:16px;bottom:14px;width:42px;height:42px;display:grid;place-items:center;padding-left:2px;border:1px solid rgba(255,255,255,.8);border-radius:50%;color:var(--ink);background:rgba(255,255,255,.92);box-shadow:0 8px 22px rgba(15,45,63,.2);font-size:13px}

.lesson-card-body{padding:21px}.lesson-card-topline{display:flex;align-items:center;justify-content:space-between;gap:16px}.lesson-card-topline>span{overflow:hidden;color:var(--blue);font-size:11px;font-weight:900;text-overflow:ellipsis;white-space:nowrap}.lesson-card-topline em{flex:0 0 auto;padding:4px 7px;color:#17705e;background:#e7f6f0;font-size:10px;font-style:normal;font-weight:900}.lesson-card-body h3{margin:8px 0 8px;font-size:23px}.lesson-card-body>p{min-height:47px;margin:0;color:#667d8c;font-size:13px;line-height:1.65}

.lesson-card-meta{display:grid;grid-template-columns:repeat(3,1fr);margin:18px 0 0;padding:14px 0;border-top:1px solid #e2eaf0;border-bottom:1px solid #e2eaf0}.lesson-card-meta>div{padding-left:12px;border-left:1px solid #e2eaf0}.lesson-card-meta>div:first-child{padding-left:0;border-left:0}.lesson-card-meta dt{font-size:16px;font-weight:900}.lesson-card-meta dd{margin:4px 0 0;color:#8596a2;font-size:10px;font-weight:800}.lesson-tag-list{display:flex;flex-wrap:wrap;gap:6px;margin-top:14px}.lesson-tag-list span{padding:5px 8px;border:1px solid #dbe6ed;color:#607889;background:#f8fbfc;font-size:10px;font-weight:800}

.lesson-card-actions{display:flex;gap:9px;margin-top:17px}.lesson-present-button,.lesson-edit-button{height:43px;display:inline-flex;align-items:center;justify-content:center;font-size:12px;font-weight:900}.lesson-present-button{flex:1;justify-content:space-between;padding:0 15px;color:#fff;background:linear-gradient(135deg,#167fae,#168c73)}.lesson-present-button i{font-size:17px;font-style:normal}.lesson-edit-button{padding:0 14px;border:1px solid #cbdbe4;color:#315f76;background:#f9fbfc}

.lesson-empty{padding:70px 20px;border:1px dashed #c8d9e3;color:#738895;background:#fff;text-align:center}.lesson-empty b,.lesson-empty span{display:block}.lesson-empty b{color:var(--ink);font-size:18px}.lesson-empty span{margin-top:7px;font-size:13px}

.lesson-side-panel{display:grid;gap:14px;position:sticky;top:18px}.lesson-role-card,.lesson-guide,.lesson-shortcuts{border:1px solid var(--line);background:#fff}.lesson-role-card{display:flex;align-items:center;gap:13px;padding:16px}.lesson-role-icon{width:44px;height:44px;display:grid;place-items:center;flex:0 0 auto;color:#fff;background:var(--blue);font-size:16px;font-weight:900}.lesson-role-card div{display:grid}.lesson-role-card small{color:#8093a0;font-size:10px;font-weight:900}.lesson-role-card b{margin-top:2px;font-size:14px}.lesson-role-card p{margin:4px 0 0;color:#718593;font-size:11px;line-height:1.5}

.lesson-guide{padding:21px}.lesson-guide-title{display:grid}.lesson-guide-title span{color:var(--green);font-size:10px;font-weight:900;letter-spacing:.15em}.lesson-guide-title b{margin-top:5px;font-size:19px}.lesson-guide ol{display:grid;gap:0;margin:17px 0 0;padding:0;list-style:none}.lesson-guide li{position:relative;display:flex;gap:12px;padding:0 0 18px}.lesson-guide li:last-child{padding-bottom:0}.lesson-guide li:not(:last-child)::after{position:absolute;top:27px;bottom:3px;left:13px;width:1px;background:#d7e5ec;content:""}.lesson-guide i{z-index:1;width:27px;height:27px;display:grid;place-items:center;flex:0 0 auto;border-radius:50%;color:#fff;background:var(--ink);font-size:10px;font-style:normal;font-weight:900}.lesson-guide li div{display:grid;padding-top:2px}.lesson-guide li b{font-size:12px}.lesson-guide li span{margin-top:3px;color:#7a8d9a;font-size:10px;line-height:1.5}

.lesson-shortcuts{padding:17px 19px}.lesson-shortcuts>b{font-size:12px}.lesson-shortcuts>div{display:flex;flex-wrap:wrap;gap:9px 13px;margin-top:11px;color:#748895;font-size:10px}.lesson-shortcuts span{display:flex;align-items:center;gap:4px}.lesson-shortcuts kbd{min-width:22px;height:22px;display:grid;place-items:center;border:1px solid #cbd9e2;border-bottom-width:2px;color:#385c71;background:#f7fafc;font:900 10px Consolas,monospace}

@media(max-width:1120px){.lesson-workspace{grid-template-columns:1fr}.lesson-side-panel{grid-template-columns:1fr 1.4fr;position:static}.lesson-shortcuts{display:none}}

@media(max-width:820px){.lesson-hub-header{align-items:flex-start;flex-direction:column}.lesson-hub-summary{width:100%;grid-template-columns:repeat(3,1fr)}.lesson-hub-summary>div:first-child{border-left:0}.lesson-toolbar{align-items:stretch;flex-direction:column}.lesson-search{width:100%}.lesson-card-grid{grid-template-columns:1fr}}

@media(max-width:600px){.lesson-hub{padding-top:20px}.lesson-hub-heading h1{font-size:36px}.lesson-hub-heading p{font-size:14px}.lesson-hub-summary>div{padding:3px 12px}.lesson-hub-summary dt{font-size:25px}.lesson-filter-group{overflow-x:auto}.lesson-filter-group button{flex:0 0 auto}.lesson-side-panel{grid-template-columns:1fr}.lesson-card-body{padding:18px}.lesson-card-meta dt{font-size:14px}}

/* 课件密码保护：保护状态、管理员设置表单与访客解锁页。 */

.lesson-card.is-protected .lesson-cover img{object-fit:contain;padding:62px;background:linear-gradient(145deg,#edf6fa,#f8fbfd)}

.lesson-cover-lock{position:absolute;right:16px;bottom:14px;width:42px;height:42px;display:grid;place-items:center;border:1px solid #fff;border-radius:50%;color:#fff;background:#173f59;box-shadow:0 8px 22px rgba(15,45,63,.24);font-size:12px;font-weight:900}

.lesson-card-topline em.protected{color:#8a5a1d;background:#fff0d5}

.lesson-access-form{display:grid;gap:10px;margin:18px -21px -21px;padding:16px 21px;border-top:1px solid #dce7ed;background:#f5f9fb}

.lesson-access-form label{display:grid;gap:6px}.lesson-access-form label span{color:#587083;font-size:10px;font-weight:900}.lesson-access-form input{height:38px;padding:0 10px;border:1px solid #cbd9e2;outline:0;color:var(--ink);background:#fff;font-size:12px}.lesson-access-form input:focus{border-color:var(--blue);box-shadow:0 0 0 3px rgba(22,134,199,.1)}

.lesson-access-form>div{display:flex;gap:7px}.lesson-access-form button{height:34px;padding:0 11px;border:0;color:#fff;background:var(--blue);font-size:11px;font-weight:900}.lesson-access-form button.remove{border:1px solid #d4dee4;color:#687d8e;background:#fff}.lesson-access-form small{color:#8596a2;font-size:9px;line-height:1.5}

.lesson-unlock-page{padding:40px 0}.lesson-unlock-card{width:min(470px,100%);padding:34px;border:1px solid #d5e2e9;background:#fff;box-shadow:0 18px 46px rgba(25,60,85,.11)}.lesson-unlock-back{display:inline-block;margin-bottom:25px;color:#557184;font-size:12px;font-weight:900}.lesson-unlock-mark{width:52px;height:52px;display:grid;place-items:center;margin-bottom:17px;border-radius:50%;color:#fff;background:var(--ink);font-size:14px;font-weight:900}.lesson-unlock-card>p{margin:0 0 8px;color:#b57624;font-size:10px;font-weight:900;letter-spacing:.16em}.lesson-unlock-card h1{margin:0 0 8px;font-size:29px}.lesson-unlock-card>span{color:#6d8291;font-size:13px;line-height:1.6}.lesson-unlock-card form{display:grid;gap:14px;margin-top:24px}.lesson-unlock-card label{display:grid;gap:7px;color:#536b7e;font-size:11px;font-weight:900}.lesson-unlock-card input{height:45px;padding:0 12px;border:1px solid #c8d8e2;outline:0;color:var(--ink);background:#fbfdfe}.lesson-unlock-card input:focus{border-color:var(--blue);box-shadow:0 0 0 3px rgba(22,134,199,.12)}.lesson-unlock-card button{height:45px;border:0;color:#fff;background:linear-gradient(135deg,#167fae,#168c73);font-weight:900}.lesson-unlock-card>small{display:block;margin-top:18px;color:#8a9aa5;font-size:10px;line-height:1.6}

@media(max-width:600px){.lesson-access-form{margin-right:-18px;margin-bottom:-18px;margin-left:-18px;padding-right:18px;padding-left:18px}.lesson-unlock-card{padding:28px 21px}}

/* 首页专业横幅的辅助说明，降低“免费”视觉权重但保留透明承诺。 */

.professional-banner > div { display:flex; align-items:center; gap:12px; flex-wrap:wrap; }

.professional-banner small { color:#6b8793; font-size:12px; font-weight:600; }

.classroom-flow{margin:34px 0 40px;padding:24px 26px;border:1px solid #d6e6ea;border-radius:20px;background:linear-gradient(125deg,#f7fbfc,#f0f8f5)}.flow-heading-row{display:flex;align-items:end;justify-content:space-between;gap:20px;margin-bottom:18px}.flow-heading-row h2{margin:0 0 5px;font-size:28px}.flow-heading-row p{margin:0;color:#6d8290;font-size:14px}.flow-badge{padding:7px 12px;border:1px solid #b9d9d6;border-radius:999px;color:#177d76;background:#fff;font-size:12px;font-weight:800;white-space:nowrap}.flow-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}.flow-grid article{display:flex;gap:14px;align-items:flex-start;padding:17px;border:1px solid #d9e8ea;border-radius:14px;background:#fff}.flow-no{color:#18867e;font-size:24px;font-weight:900;line-height:1}.flow-grid h3{margin:0 0 5px;color:#163e57;font-size:16px}.flow-grid p{margin:0;color:#718594;font-size:12px;line-height:1.6}@media(max-width:760px){.classroom-flow{padding:20px 16px}.flow-heading-row{display:block}.flow-badge{display:inline-block;margin-top:12px}.flow-grid{grid-template-columns:1fr}.flow-grid article{padding:14px}}



.diagram-uniform-acceleration-formula{background-image:var(--thumbnail-load,url("/static/model-thumbnails/uniform-acceleration-formula.svg"))}



.diagram-cart-force-inference{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cart-force-inference.png"))}

.diagram-force-decomposition{background-image:var(--thumbnail-load,url("/static/model-thumbnails/force-decomposition.png"))}

.diagram-friction-direction{background-image:var(--thumbnail-load,url("/static/model-thumbnails/friction-direction.png"))}

.diagram-force-composition{background-image:var(--thumbnail-load,url("/static/model-thumbnails/force-composition-thumb.webp"));background-size:cover;background-position:center}

.diagram-hooke-law{background-image:var(--thumbnail-load,url("/static/model-thumbnails/hooke-law-thumb.webp"))}

.diagram-galileo-incline{background-image:var(--thumbnail-load,url("/static/model-thumbnails/galileo-incline.svg"))}



.diagram-static-friction-threshold{background-image:var(--thumbnail-load,url("/static/model-thumbnails/static-friction-threshold-thumb.webp"));background-size:cover;background-position:center}



.diagram-sliding-friction-control{background-image:var(--thumbnail-load,url("/static/model-thumbnails/sliding-friction-control-thumb.webp"));background-size:cover;background-position:center}



/* 双绳悬挂：独立科学示意缩略图。 */

.diagram-force-step-response{background-image:var(--thumbnail-load,url("/static/model-thumbnails/force-step-response.svg"));background-size:cover;background-position:center}

.diagram-force-step-response .part{display:none}

.diagram-double-rope-tension{background-image:var(--thumbnail-load,url("/static/model-thumbnails/double-rope-tension.png"));background-size:cover;background-position:center}

.diagram-double-rope-tension .part{display:none}



.diagram-three-force-equilibrium{background-image:var(--thumbnail-load,url("/static/model-thumbnails/three-force-equilibrium.png"))}



.diagram-acceleration-force-mass{background-image:var(--thumbnail-load,url("/static/model-thumbnails/acceleration-force-mass.svg"))}



.diagram-force-to-motion{background-image:var(--thumbnail-load,url("/static/model-thumbnails/force-to-motion.svg"));background-size:cover;background-position:center}.diagram-force-to-motion .part{display:none}



/* 电梯模型：超重与失重的独立科学封面。 */

.diagram-elevator-apparent-weight{background-image:var(--thumbnail-load,url("/static/model-thumbnails/elevator-apparent-weight.svg"))}



/* 必修二第一章：缩略图来自各模型的科学示意 SVG。 */

.diagram-projectile{background-image:var(--thumbnail-load,url("/static/model-thumbnails/projectile-motion.png"));background-size:cover;background-position:center}

.diagram-projectile .part{display:none}



.diagram-curvilinear-motion{background-image:var(--thumbnail-load,url("/static/model-thumbnails/curvilinear-motion.png"));background-size:cover;background-position:center}.diagram-curvilinear-motion .part{display:none}



.diagram-motion-composition{background-image:var(--thumbnail-load,url("/static/model-thumbnails/motion-composition.png?v=20260922-apparatus"));background-size:cover;background-position:center}.diagram-motion-composition .part{display:none}



.diagram-projectile-experiment{background-image:var(--thumbnail-load,url("/static/model-thumbnails/projectile-experiment.png?v=20260922-3d"));background-size:cover;background-position:center}.diagram-projectile-experiment .part{display:none}



.diagram-projectile-applications{background-image:var(--thumbnail-load,url("/static/model-thumbnails/projectile-applications.png?v=20260922-3d"));background-size:cover;background-position:center}.diagram-projectile-applications .part{display:none}



/* 小船渡河：缩略图由模型的恒定速度合成关系绘制。 */

.diagram-river-crossing{background-image:var(--thumbnail-load,url("/static/model-thumbnails/river-crossing.png"))}



/* 喷泉与跳远模型缩略图。 */

.diagram-oblique-throw{background-image:var(--thumbnail-load,url("/static/model-thumbnails/oblique-throw.png?v=20260922-3d"));background-size:cover;background-position:center}.diagram-oblique-throw .part{display:none}



.diagram-transmission{background-image:var(--thumbnail-load,url("/static/model-thumbnails/transmission.svg"));background-size:cover;background-position:center}.diagram-transmission .part{display:none}



/* 向心力因素探究：双组俯视轨道与同尺度测力图。 */

.diagram-centripetal-force-factors{background-image:var(--thumbnail-load,url("/static/model-thumbnails/centripetal-force-factors.svg"));background-size:cover;background-position:center}.diagram-centripetal-force-factors .part{display:none}



/* 汽车过桥：同速对照拱桥与凹形路面的真实模型示意。 */

.diagram-car-bridge{background-image:var(--thumbnail-load,url("/static/model-thumbnails/car-bridge.svg"))}



.diagram-circular-speed-period{background-image:var(--thumbnail-load,url("/static/model-thumbnails/circular-speed-period.png"));background-size:cover;background-position:center}.diagram-circular-speed-period .part{display:none}



/* 离心现象：统一三情景缩略图。 */

.diagram-centrifugal-release{background-image:var(--thumbnail-load,url("/static/model-thumbnails/centrifugal-release.svg"));background-size:cover;background-position:center}.diagram-centrifugal-release .part{display:none}



/* 汽车与火车过弯：门户缩略图与新模型保持一致。 */

.diagram-vehicle-turning{background:#edf4f6 url("/static/model-thumbnails/vehicle-turning.svg?v=20260907") center/cover no-repeat;}

.diagram-vehicle-turning>*{display:none;}



.diagram-universal-gravitation{background-image:var(--thumbnail-load,url("/static/model-thumbnails/universal-gravitation.svg?v=20260907"))}



.diagram-geostationary-satellite{background-image:var(--thumbnail-load,url("/static/model-thumbnails/geostationary-satellite.svg"));background-size:cover;background-position:center}.diagram-geostationary-satellite .part{display:none}



/* 开普勒实验室：真实轨道画面缩略图。 */

.diagram-kepler-laws{background-image:var(--thumbnail-load,url("/static/model-thumbnails/kepler-laws.png"));background-size:cover;background-position:center}.diagram-kepler-laws .part{display:none}



.diagram-newton-cannon{background-image:var(--thumbnail-load,url("/static/model-thumbnails/newton-cannon.svg"))}



/* 天体质量：观测轨道与质量推理同屏缩略图。 */

.diagram-celestial-mass{background:#edf4f5 url("/static/model-thumbnails/celestial-mass.svg") center/cover no-repeat}.diagram-celestial-mass>*{display:none}



.diagram-gravity-latitude{background:#eef5f5 url("/static/model-thumbnails/gravity-latitude.svg?v=20260907") center/cover no-repeat}.diagram-gravity-latitude>*{display:none}



/* 邮箱账号可能比原用户名更长，公共账号信息允许换行或省略，避免挤出导航。 */

.user-pill{max-width:230px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}

.member-admin-identity,.account-summary{min-width:0;overflow-wrap:anywhere}

.account-summary h1{overflow-wrap:anywhere}

.email-preference{margin:20px 0;font-size:16px;line-height:1.6}

.email-preference button{min-height:44px;padding:8px 16px;border:1px solid #a1bdce;border-radius:8px;background:#eaf4fb;color:#174a69;font-size:16px;cursor:pointer}

@media(max-width:900px){.site-header nav .nav-account{display:inline-flex!important;align-items:center;min-height:44px}}



/* 坐标系模型：空间坐标与初末位移的原理缩略图。 */

.diagram-coordinate-system{background-image:var(--thumbnail-load,url("/static/model-thumbnails/coordinate-system.svg"))}



/* 经典版使用旧版真实实验画面，与新版缩略图区分。 */









/* 八年级上册声学探究封面。 */











/* 必修一第一章：复习题组的真实构图封面。 */

.diagram-motion-description-review{background-image:var(--thumbnail-load,url("/static/model-thumbnails/motion-description-review.svg?v=20260912"))}



/* 长度测量：尺上读数与两端之差。 */



















.diagram-thermometer-measurement{background-image:var(--thumbnail-load,url("/static/model-thumbnails/thermometer-measurement.svg?v=20260909"));}


.diagram-melting-solidification{background-image:var(--thumbnail-load,url("/static/model-thumbnails/melting-solidification.svg?v=20260910"));}

.diagram-water-boiling{background-image:var(--thumbnail-load,url("/static/model-thumbnails/water-boiling.svg?v=20260910"));}

.diagram-evaporation-cooling{background-image:var(--thumbnail-load,url("/static/model-thumbnails/evaporation-cooling.svg?v=20260910"));}

.diagram-condensation-white-mist{background-image:var(--thumbnail-load,url("/static/model-thumbnails/condensation-white-mist.svg?v=20260910"));}

.diagram-sublimation-deposition{background-image:var(--thumbnail-load,url("/static/model-thumbnails/sublimation-deposition.svg?v=20260910"));}

.diagram-phase-change-review{background-image:var(--thumbnail-load,url("/static/model-thumbnails/phase-change-review.svg?v=20260910"));}

.diagram-straight-light-shadow{background-image:var(--thumbnail-load,url("/static/model-thumbnails/straight-light-shadow.svg?v=20260910"));}

.diagram-pinhole-imaging{background-image:var(--thumbnail-load,url("/static/model-thumbnails/pinhole-imaging.svg?v=20260910"));}

.diagram-light-reflection{background-image:var(--thumbnail-load,url("/static/model-thumbnails/light-path.svg?v=20260910"));}
.diagram-plane-mirror-experiment{background-image:var(--thumbnail-load,url("/static/model-thumbnails/plane-mirror.svg?v=20260910"));}
.diagram-light-refraction{background-image:var(--thumbnail-load,url("/static/model-thumbnails/light-refraction.svg?v=20260910"));}
.diagram-apparent-depth{background-image:var(--thumbnail-load,url("/static/model-thumbnails/apparent-depth.svg?v=20260910"));}
.diagram-light-colors{background-image:var(--thumbnail-load,url("/static/model-thumbnails/light-colors.svg?v=20260910"));}
.diagram-light-phenomena-review{background-image:var(--thumbnail-load,url("/static/model-thumbnails/light-phenomena-review.svg?v=20260910"));}
.diagram-invisible-light{background-image:var(--thumbnail-load,url("/static/model-thumbnails/invisible-light.svg?v=20260910"));}

/* 高中化学第一章：使用本次模型实际界面的缩略图。 */
.diagram-chemistry-classification{background-image:var(--thumbnail-load,url("/static/model-thumbnails/chemistry-classification.png?v=20260910"));background-size:contain;background-position:center;background-repeat:no-repeat;background-color:#eff5f5}.diagram-chemistry-classification .part{display:none}
.diagram-colloid-tyndall{background-image:var(--thumbnail-load,url("/static/model-thumbnails/colloid-tyndall.png?v=20260910"));background-size:contain;background-position:center;background-repeat:no-repeat;background-color:#eff5f5}.diagram-colloid-tyndall .part{display:none}
.diagram-chemical-transformation-routes{background-image:var(--thumbnail-load,url("/static/model-thumbnails/chemical-transformation-routes.png?v=20260910"));background-size:contain;background-position:center;background-repeat:no-repeat;background-color:#eff5f5}.diagram-chemical-transformation-routes .part{display:none}
.diagram-electrolyte-ionization{background-image:var(--thumbnail-load,url("/static/model-thumbnails/electrolyte-ionization.png?v=20260910"));background-size:contain;background-position:center;background-repeat:no-repeat;background-color:#eff5f5}.diagram-electrolyte-ionization .part{display:none}
.diagram-ionic-reaction-essence{background-image:var(--thumbnail-load,url("/static/model-thumbnails/ionic-reaction-essence.png?v=20260910"));background-size:contain;background-position:center;background-repeat:no-repeat;background-color:#eff5f5}.diagram-ionic-reaction-essence .part{display:none}
.diagram-ionic-equation-workbench{background-image:var(--thumbnail-load,url("/static/model-thumbnails/ionic-equation-workbench.png?v=20260910"));background-size:contain;background-position:center;background-repeat:no-repeat;background-color:#eff5f5}.diagram-ionic-equation-workbench .part{display:none}
.diagram-barium-acid-conductivity{background-image:var(--thumbnail-load,url("/static/model-thumbnails/barium-acid-conductivity.png?v=20260910"));background-size:contain;background-position:center;background-repeat:no-repeat;background-color:#eff5f5}.diagram-barium-acid-conductivity .part{display:none}
.diagram-redox-electron-transfer{background-image:var(--thumbnail-load,url("/static/model-thumbnails/redox-electron-transfer.png?v=20260910"));background-size:contain;background-position:center;background-repeat:no-repeat;background-color:#eff5f5}.diagram-redox-electron-transfer .part{display:none}
.diagram-iron-copper-redox{background-image:var(--thumbnail-load,url("/static/model-thumbnails/iron-copper-redox.png?v=20260910"));background-size:contain;background-position:center;background-repeat:no-repeat;background-color:#eff5f5}.diagram-iron-copper-redox .part{display:none}
.diagram-matter-changes-review{background-image:var(--thumbnail-load,url("/static/model-thumbnails/matter-changes-review.png?v=20260910"));background-size:contain;background-position:center;background-repeat:no-repeat;background-color:#eff5f5}.diagram-matter-changes-review .part{display:none}

.diagram-air-oxygen-measurement{background-image:var(--thumbnail-load,url("/static/model-thumbnails/air-oxygen-measurement.svg?v=20260910"));}

.diagram-temporary-slide-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/temporary-slide-lab.svg"));background-size:cover;background-position:center}.diagram-temporary-slide-lab>*{display:none}

/* 九上化学第一单元真实模型缩略图 */
.diagram-physical-chemical-changes{background-image:var(--thumbnail-load,url("/static/model-thumbnails/physical-chemical-changes.png?v=20260911"));background-size:contain;background-position:center;background-repeat:no-repeat;background-color:#edf5f7}.diagram-physical-chemical-changes .part{display:none}
.diagram-candle-burning-inquiry{background-image:var(--thumbnail-load,url("/static/model-thumbnails/candle-burning-inquiry.png?v=20260911"));background-size:contain;background-position:center;background-repeat:no-repeat;background-color:#edf5f7}.diagram-candle-burning-inquiry .part{display:none}
.diagram-chemical-reagent-handling{background-image:var(--thumbnail-load,url("/static/model-thumbnails/chemical-reagent-handling.png?v=20260911"));background-size:contain;background-position:center;background-repeat:no-repeat;background-color:#edf5f7}.diagram-chemical-reagent-handling .part{display:none}
.diagram-measuring-cylinder-reading{background-image:var(--thumbnail-load,url("/static/model-thumbnails/measuring-cylinder-reading.png?v=20260911"));background-size:contain;background-position:center;background-repeat:no-repeat;background-color:#edf5f7}.diagram-measuring-cylinder-reading .part{display:none}
.diagram-alcohol-lamp-heating{background-image:var(--thumbnail-load,url("/static/model-thumbnails/alcohol-lamp-heating.png?v=20260911"));background-size:contain;background-position:center;background-repeat:no-repeat;background-color:#edf5f7}.diagram-alcohol-lamp-heating .part{display:none}
.diagram-apparatus-airtightness{background-image:var(--thumbnail-load,url("/static/model-thumbnails/apparatus-airtightness.png?v=20260911"));background-size:contain;background-position:center;background-repeat:no-repeat;background-color:#edf5f7}.diagram-apparatus-airtightness .part{display:none}
.diagram-oxygen-carbon-dioxide-properties{background-image:var(--thumbnail-load,url("/static/model-thumbnails/oxygen-carbon-dioxide-properties.png?v=20260911"));background-size:contain;background-position:center;background-repeat:no-repeat;background-color:#edf5f7}.diagram-oxygen-carbon-dioxide-properties .part{display:none}
.diagram-enter-chemistry-review{background-image:var(--thumbnail-load,url("/static/model-thumbnails/enter-chemistry-review.png?v=20260911"));background-size:contain;background-position:center;background-repeat:no-repeat;background-color:#edf5f7}.diagram-enter-chemistry-review .part{display:none}

.diagram-combustion-in-oxygen{background-image:var(--thumbnail-load,url("/static/model-thumbnails/combustion-in-oxygen.svg?v=20260910"));}

.diagram-paramecium-life-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/paramecium-life-lab.svg"));background-size:cover;background-position:center}
.diagram-paramecium-life-lab>*{display:none}

.diagram-catalyst-investigation{background-image:var(--thumbnail-load,url("/static/model-thumbnails/catalyst-investigation.svg?v=20260910"));}

.diagram-seed-dissection-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/seed-dissection-lab.svg"));background-size:cover;background-position:center}
.diagram-seed-dissection-lab>*{display:none}

.diagram-cell-structure-explorer{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cell-structure-explorer.svg"));background-size:cover;background-position:center}
.diagram-cell-structure-explorer>*{display:none}

.diagram-cell-life-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cell-life-lab.svg"));background-size:cover;background-position:center}
.diagram-cell-life-lab>*{display:none}

.diagram-air-composition{background-image:var(--thumbnail-load,url("/static/model-thumbnails/air-composition.svg?v=20260910"));}

.diagram-liquid-air-separation{background-image:var(--thumbnail-load,url("/static/model-thumbnails/liquid-air-separation.svg?v=20260910"));}

.diagram-cell-development-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cell-development-lab.svg"));background-size:cover;background-position:center}
.diagram-cell-development-lab>*{display:none}

.diagram-air-quality-station{background-image:var(--thumbnail-load,url("/static/model-thumbnails/air-quality-station.svg?v=20260911"));}

.diagram-organism-structure-levels{background-image:var(--thumbnail-load,url("/static/model-thumbnails/organism-structure-levels.svg"));background-size:cover;background-position:center}
.diagram-organism-structure-levels>*{display:none}

.diagram-air-oxygen-review{background-image:var(--thumbnail-load,url("/static/model-thumbnails/air-oxygen-review.svg?v=20260911"));}

.diagram-microscope-observation-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/microscope-observation-lab.svg"));background-size:cover;background-position:center}
.diagram-microscope-observation-lab>*{display:none}

.diagram-plant-groups-explorer{background-image:var(--thumbnail-load,url("/static/model-thumbnails/plant-groups-explorer.svg"));background-size:cover;background-position:center}
.diagram-plant-groups-explorer>*{display:none}

.diagram-fish-swimming-respiration{background-image:var(--thumbnail-load,url("/static/model-thumbnails/fish-swimming-respiration.svg"));background-size:cover;background-position:center}
.diagram-fish-swimming-respiration>*{display:none}

.diagram-bird-respiration-air-sacs{background-image:var(--thumbnail-load,url("/static/model-thumbnails/bird-respiration-air-sacs.png"));background-size:cover;background-position:center}
.diagram-bird-respiration-air-sacs>*{display:none}

.diagram-microbe-culture-controls{background-image:var(--thumbnail-load,url("/static/model-thumbnails/microbe-culture-controls.svg"));background-size:cover;background-position:center}
.diagram-microbe-culture-controls>*{display:none}

.diagram-microorganism-comparison{background-image:var(--thumbnail-load,url("/static/model-thumbnails/microorganism-comparison.svg"));background-size:cover;background-position:center}
.diagram-microorganism-comparison>*{display:none}

.diagram-yeast-fermentation-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/yeast-fermentation-lab.svg"));background-size:cover;background-position:center}
.diagram-yeast-fermentation-lab>*{display:none}

.diagram-life-characteristics-garden{background-image:var(--thumbnail-load,url("/static/model-thumbnails/life-characteristics-garden.svg"));background-size:cover;background-position:center}
.diagram-life-characteristics-garden>*{display:none}

.diagram-biological-classification-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/biological-classification-lab.svg"));background-size:cover;background-position:center}
.diagram-biological-classification-lab>*{display:none}

.diagram-orbital-flight-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/orbital-flight-3d-thumb.webp"));background-size:cover;background-position:center}
.diagram-orbital-flight-3d>*{display:none}

.diagram-unit-conversion{background-image:var(--thumbnail-load,url("/static/model-thumbnails/unit-conversion.svg"));background-size:cover;background-position:center}.diagram-unit-conversion .part{display:none}

.diagram-vt-area-displacement{background-image:var(--thumbnail-load,url("/static/model-thumbnails/vt-area-displacement.svg"));background-size:cover;background-position:center}

.diagram-inclined-chute-displacement{background-image:var(--thumbnail-load,url("/static/model-thumbnails/inclined-chute-displacement.png"))}

.diagram-earth-explorer-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/earth-explorer-3d-thumb.webp"));background-size:cover;background-position:center}.diagram-earth-explorer-3d>*{display:none}

.diagram-photogate-speed-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/photogate-speed-3d.png"))}



.diagram-magnifier-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/magnifier-3d.png?v=optics-dark-20260913"));background-size:cover;background-position:center}.diagram-magnifier-3d .part{display:none}
.diagram-projector-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/projector-3d.png?v=optics-dark-20260913"));background-size:cover;background-position:center}.diagram-projector-3d .part{display:none}
.diagram-microscope-optics-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/microscope-optics-3d.png?v=optics-first-image-20260913"));background-size:cover;background-position:center}.diagram-microscope-optics-3d .part{display:none}
.diagram-telescope-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/telescope-3d.png?v=optics-first-image-20260913"));background-size:cover;background-position:center}.diagram-telescope-3d .part{display:none}

/* 3D实验缩略图使用实际场景截图，入口与独立slug一致。 */
.diagram-ticker-timer-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/ticker-timer-3d.png"));background-size:cover;background-position:center}.diagram-ticker-timer-3d .part{display:none}

/* 弹簧振子精密实验台独立入口 */

/* 双目显微镜结构（3D）：缩略图用实际三维场景截图。 */
.diagram-microscope-structure-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/microscope-structure-3d.png?v=20260915b"));background-size:cover;background-position:center}.diagram-microscope-structure-3d .part{display:none}
/* 门户页面使用细窄透明轨道，保留原生拖动；不影响模型和弹窗内部滚动。 */
html::-webkit-scrollbar{width:6px;height:6px}
html::-webkit-scrollbar-track{background:transparent}
html::-webkit-scrollbar-thumb{background:rgba(72,108,120,.24);border-radius:6px}
html::-webkit-scrollbar-thumb:hover{background:rgba(72,108,120,.5)}
html::-webkit-scrollbar-thumb:active{background:rgba(72,108,120,.7)}
html::-webkit-scrollbar-button{display:none}
html::-webkit-scrollbar-corner{background:transparent}
@supports not selector(::-webkit-scrollbar){html{scrollbar-width:thin;scrollbar-color:rgba(72,108,120,.3) transparent}}
@media(forced-colors:active){html{scrollbar-width:auto;scrollbar-color:auto}html::-webkit-scrollbar{width: auto;height:auto}html::-webkit-scrollbar-thumb{background:ButtonText}}

/* 首屏外缩略图由观察器解除开关；背景尺寸与卡片布局保持不变。 */
.science-home [data-thumbnail-pending]{--thumbnail-load:none}



.diagram-helicopter-reference-frame{background-image:var(--thumbnail-load,url("/static/model-thumbnails/helicopter-reference-frame.svg"));background-size:cover;background-position:center}
.diagram-helicopter-reference-frame>*{display:none}



.diagram-motion-ratios{background-image:var(--thumbnail-load,url("/static/model-thumbnails/motion-ratios.svg"));background-size:cover;background-position:center}

.diagram-gasoline-engine-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/gasoline-engine-3d.png?v=20260920"));background-size:cover;background-position:center}.diagram-gasoline-engine-3d .part{display:none}

/* 第三章：本地制作中的弹力器材截图，由缩略图观察器按需加载。 */
.diagram-elastic-contact-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/elastic-contact-3d-thumb.webp"));background-size:cover;background-position:center}

/* 牛顿第三定律：使用真实仿真场景截图作入口封面。 */
.diagram-newton-third-law{background-image:var(--thumbnail-load,url("/static/model-thumbnails/newton-third-law.png"));background-size:cover;background-position:center}.diagram-newton-third-law .part{display:none}

.diagram-projectile-comparison-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/projectile-comparison-3d.png?v=20260922"));background-size:cover;background-position:center}.diagram-projectile-comparison-3d .part{display:none}

.diagram-force-analysis-trainer{background-image:var(--thumbnail-load,url("/static/model-thumbnails/force-analysis-trainer-thumb.webp"));background-size:cover;background-position:center}

.diagram-buoyancy-experiment-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/buoyancy-experiment-3d.png"));background-size:cover;background-position:center}.diagram-buoyancy-experiment-3d .part{display:none}

/* 弹簧测力计入口使用本地仿真截图，随门户缩略图按需加载。 */
.diagram-spring-balance-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/spring-balance-3d.png"));background-size:cover;background-position:center}.diagram-spring-balance-3d .part{display:none}



.diagram-archimedes-experiment-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/archimedes-experiment-3d.png"));background-size:cover;background-position:center}.diagram-archimedes-experiment-3d .part{display:none}

.diagram-specific-heat-capacity{background-image:var(--thumbnail-load,url("/static/model-thumbnails/specific-heat-capacity.png"));background-size:cover;background-position:center}.diagram-specific-heat-capacity .part{display:none}
.diagram-molecular-thermal-motion{background-image:var(--thumbnail-load,url("/static/model-thumbnails/molecular-thermal-motion.png"));background-size:cover;background-position:center}.diagram-molecular-thermal-motion .part{display:none}
.diagram-internal-energy-change{background-image:var(--thumbnail-load,url("/static/model-thumbnails/internal-energy-change.png"));background-size:cover;background-position:center}.diagram-internal-energy-change .part{display:none}

.diagram-two-force-balance-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/two-force-balance-3d.png"));background-size:cover;background-position:center}.diagram-two-force-balance-3d .part{display:none}

.diagram-float{background-image:var(--thumbnail-load,url("/static/model-thumbnails/float.png?v=a8e16c4406b0"));background-size:cover;background-position:center}.diagram-float .part{display:none}

.diagram-pressure-effect-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/pressure-effect-3d.png"));background-size:cover;background-position:center}.diagram-pressure-effect-3d .part{display:none}

.diagram-friction{background-image:var(--thumbnail-load,url("/static/model-thumbnails/friction.png"));background-size:cover;background-position:center}.diagram-friction .part{display:none}

.diagram-lever{background-image:var(--thumbnail-load,url("/static/model-thumbnails/lever.png?v=f8efec9f62d4"));background-size:cover;background-position:center}.diagram-lever .part{display:none}


.diagram-current-measurement{background-image:var(--thumbnail-load,url("/static/model-thumbnails/current-measurement.png"));background-size:cover;background-position:center}.diagram-current-measurement .part{display:none}

.diagram-communicating-vessels-ship-lock{background-image:var(--thumbnail-load,url("/static/model-thumbnails/communicating-vessels-ship-lock.png"));background-size:cover;background-position:center}.diagram-communicating-vessels-ship-lock .part{display:none}

.diagram-work-power{background-image:var(--thumbnail-load,url("/static/model-thumbnails/work-power.jpg"));background-size:cover;background-position:center}.diagram-work-power .part{display:none}

.diagram-kinetic-energy-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/kinetic-energy-3d.jpg"));background-size:cover;background-position:center}.diagram-kinetic-energy-3d .part{display:none}

.diagram-voltage-measurement{background-image:var(--thumbnail-load,url("/static/model-thumbnails/voltage-measurement.png"));background-size:cover;background-position:center}.diagram-voltage-measurement .part{display:none}

.diagram-potential-energy-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/potential-energy-3d.jpg"));background-size:cover;background-position:center}.diagram-potential-energy-3d .part{display:none}



.diagram-resistor{background-image:var(--thumbnail-load,url("/static/model-thumbnails/rheostat.png"));background-size:cover;background-position:center}.diagram-resistor .part{display:none}

.diagram-current-voltage-relationship{background-image:var(--thumbnail-load,url("/static/model-thumbnails/current-voltage-relationship.png"));background-size:cover;background-position:center}.diagram-current-voltage-relationship .part{display:none}

.diagram-buoyancy-applications-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/buoyancy-applications-3d.jpg"));background-size:cover;background-position:center}.diagram-buoyancy-applications-3d .part{display:none}

.diagram-resistance-measurement{background-image:var(--thumbnail-load,url("/static/model-thumbnails/resistance-measurement.png"));background-size:cover;background-position:center}.diagram-resistance-measurement .part{display:none}

.diagram-lamp-power{background-image:var(--thumbnail-load,url("/static/model-thumbnails/lamp-power.png"));background-size:cover;background-position:center}.diagram-lamp-power .part{display:none}



.diagram-fluid-pressure-speed{background-image:var(--thumbnail-load,url("/static/model-thumbnails/fluid-pressure-speed.png"));background-size:cover;background-position:center}.diagram-fluid-pressure-speed .part{display:none}

.diagram-circuit-diagnosis{background-image:var(--thumbnail-load,url("/static/model-thumbnails/circuit-diagnosis.png"));background-size:cover;background-position:center}.diagram-circuit-diagnosis .part{display:none}

.diagram-steelyard-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/steelyard-3d.jpg"));background-size:cover;background-position:center}.diagram-steelyard-3d .part{display:none}



.diagram-force-effects-elements{background-image:var(--thumbnail-load,url("/static/model-thumbnails/force-effects-elements.png"));background-size:cover;background-position:center}.diagram-force-effects-elements .part{display:none}

.diagram-dimming-lamp{background-image:var(--thumbnail-load,url("/static/model-thumbnails/dimming-lamp.png"));background-size:cover;background-position:center}.diagram-dimming-lamp .part{display:none}

.diagram-junior-gravity{background-image:var(--thumbnail-load,url("/static/model-thumbnails/junior-gravity.png"));background-size:cover;background-position:center}.diagram-junior-gravity .part{display:none}

.diagram-energy-meter{background-image:var(--thumbnail-load,url("/static/model-thumbnails/energy-meter.png"));background-size:cover;background-position:center}.diagram-energy-meter .part{display:none}

.diagram-collinear-forces{background-image:var(--thumbnail-load,url("/static/model-thumbnails/collinear-forces.png"));background-size:cover;background-position:center}.diagram-collinear-forces .part{display:none}




.diagram-household-circuit-design{background-image:var(--thumbnail-load,url("/static/model-thumbnails/household-circuit-design.png"));background-size:cover;background-position:center}.diagram-household-circuit-design .part{display:none}

.diagram-fuel-heat-value-efficiency{background-image:var(--thumbnail-load,url("/static/model-thumbnails/fuel-heat-value-efficiency.png"));background-size:cover;background-position:center}.diagram-fuel-heat-value-efficiency .part{display:none}
.diagram-simple-heat-engine-build{background-image:var(--thumbnail-load,url("/static/model-thumbnails/simple-heat-engine-build.png"));background-size:cover;background-position:center}.diagram-simple-heat-engine-build .part{display:none}

.diagram-motor-generator-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/motor-generator-3d.jpg"))}

/* 修改前互动模型的独立封面与编号入口。 */
.diagram-circuits-classic{background-image:var(--thumbnail-load,url("/static/model-thumbnails/circuits-classic.jpg"));background-size:cover;background-position:center}.diagram-circuits-classic .part{display:none}
.diagram-piston-pump-classic{background-image:var(--thumbnail-load,url("/static/model-thumbnails/piston-pump-classic.jpg"));background-size:cover;background-position:center}.diagram-piston-pump-classic .part{display:none}
.diagram-efficiency-classic{background-image:var(--thumbnail-load,url("/static/model-thumbnails/efficiency-classic.jpg"));background-size:cover;background-position:center}.diagram-efficiency-classic .part{display:none}
.diagram-inertia-classic{background-image:var(--thumbnail-load,url("/static/model-thumbnails/inertia-classic.jpg"));background-size:cover;background-position:center}.diagram-inertia-classic .part{display:none}
.diagram-atmosphere-classic{background-image:var(--thumbnail-load,url("/static/model-thumbnails/atmosphere-classic.jpg"));background-size:cover;background-position:center}.diagram-atmosphere-classic .part{display:none}
.diagram-household-circuit-classic{background-image:var(--thumbnail-load,url("/static/model-thumbnails/household-circuit-classic.jpg"));background-size:cover;background-position:center}.diagram-household-circuit-classic .part{display:none}
.diagram-gasoline-engine-classic{background-image:var(--thumbnail-load,url("/static/model-thumbnails/gasoline-engine-classic.png"));background-size:cover;background-position:center}.diagram-gasoline-engine-classic .part{display:none}
.diagram-rheostat-classic{background-image:var(--thumbnail-load,url("/static/model-thumbnails/rheostat-classic.png"));background-size:cover;background-position:center}.diagram-rheostat-classic .part{display:none}

.diagram-precision-measurement-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/precision-measurement-3d.jpg"));background-size:cover;background-position:center}.diagram-precision-measurement-3d .part{display:none}




.diagram-chemistry-titration{background-image:var(--thumbnail-load,url("/static/model-thumbnails/chemistry-titration.jpg"));background-size:cover;background-position:center}
.diagram-chemistry-titration .part{display:none}

.diagram-solution-preparation{background-image:var(--thumbnail-load,url("/static/model-thumbnails/solution-preparation.jpg"));background-size:cover;background-position:center}
.diagram-solution-preparation .part{display:none}




.diagram-periodic-elements-lab{background:#17222d var(--thumbnail-load,url("/static/model-thumbnails/periodic-elements-lab.png")) center/cover no-repeat}
.diagram-periodic-elements-lab .part{display:none}




.diagram-air-wedge-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/air-wedge-3d.png"));background-size:cover;background-position:center}
.diagram-air-wedge-3d .part{display:none}

.diagram-cyclotron-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cyclotron-3d.png"));background-size:cover;background-position:center}
.diagram-cyclotron-3d .part{display:none}

.diagram-chlorine-water-bleaching{background-image:var(--thumbnail-load,url("/static/model-thumbnails/chlorine-water-bleaching-thumb.webp"));background-size:cover;background-position:center}

.diagram-mole-particle-bridge{background-image:var(--thumbnail-load,url("/static/model-thumbnails/mole-particle-bridge-thumb.webp"));background-size:cover;background-position:center}

.diagram-chloride-ion-test{background-image:var(--thumbnail-load,url("/static/model-thumbnails/chloride-ion-test-thumb.webp"));background-size:cover;background-position:center}

.diagram-gas-molar-volume{background-image:var(--thumbnail-load,url("/static/model-thumbnails/gas-molar-volume-thumb.webp"));background-size:cover;background-position:center}

.diagram-chlorine-reactions{background-image:var(--thumbnail-load,url("/static/model-thumbnails/chlorine-reactions-thumb.webp"));background-size:cover;background-position:center}

.diagram-sodium-compounds{background-image:var(--thumbnail-load,url("/static/model-thumbnails/sodium-compounds.png?v=20260917"));background-size:cover;background-position:center;background-color:#edf3f0}
.diagram-sodium-compounds .part{display:none}
.diagram-sodium-compounds{background-image:var(--thumbnail-load,url("/static/model-thumbnails/sodium-compounds-v2.webp"))!important;background-size:cover;background-position:center}

.diagram-reaction{background-image:var(--thumbnail-load,url("/static/model-thumbnails/reaction-thumb.webp"))}
.diagram-reaction{background-image:var(--thumbnail-load,url("/static/model-thumbnails/reaction-micro-v2-thumb.webp"));background-size:cover;background-position:center}
.diagram-reaction .part{display:none}

.diagram-gas-apparatus{background-image:var(--thumbnail-load,url("/static/model-thumbnails/gas-apparatus-thumb.webp"))!important;background-size:cover;background-position:center}
.diagram-gas-apparatus .part{display:none}

.diagram-mass{background-image:var(--thumbnail-load,url("/static/model-thumbnails/mass-conservation-v2-thumb.webp"))}

.diagram-balance{background-image:var(--thumbnail-load,url("/static/model-thumbnails/equation-balancing-v2-thumb.webp"))!important}



.diagram-electrolysis{background-image:var(--thumbnail-load,url("/static/model-thumbnails/water-electrolysis-v2-thumb.webp"))!important}



.diagram-oxygen{background-image:var(--thumbnail-load,url("/static/model-thumbnails/oxygen-preparation-v2-thumb.webp"))!important}

.diagram-solubility{background-image:var(--thumbnail-load,url("/static/model-thumbnails/solubility-v2-thumb.webp"))!important}

.diagram-ph{background-image:var(--thumbnail-load,url("/static/model-thumbnails/ph-v2-thumb.webp"))!important}

.diagram-metal{background-image:var(--thumbnail-load,url("/static/model-thumbnails/metal-v2-thumb.webp"))!important}

.diagram-rust{background-image:var(--thumbnail-load,url("/static/model-thumbnails/rust-v2-thumb.webp"))!important}

.diagram-co-reduction{background-image:url("/static/model-thumbnails/co-reduction-v2-thumb.webp")!important}










.diagram-charcoal-reduction{background-image:url("/static/model-thumbnails/charcoal-reduction-v2-thumb.webp")!important}





.diagram-salt-purification{background-image:url("/static/model-thumbnails/crude-salt-v2-thumb.webp")!important}









.diagram-purification{background-image:url("/static/model-thumbnails/water-purification-v2-thumb.webp")!important}

















.diagram-alveolar-exchange{background-image:var(--thumbnail-load,url("/static/model-thumbnails/respiratory-movement-alveolar-exchange.svg"))}
.diagram-alveolar-exchange{background:#293b36;background-image:var(--thumbnail-load,url("/static/model-thumbnails/alveolar-exchange.png"));background-size:contain;background-position:center;background-repeat:no-repeat}
.diagram-alveolar-exchange .part{display:none}
.diagram-alveolar-exchange{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/alveolar-exchange-png-330403fc2055.webp"))}

.diagram-urine-formation{background-image:var(--thumbnail-load,url("/static/model-thumbnails/urine-formation.svg"))}
.diagram-urine-formation{background:#2b3b32;background-image:var(--thumbnail-load,url("/static/model-thumbnails/urine-formation.png"));background-size:contain;background-position:center;background-repeat:no-repeat}
.diagram-urine-formation .part{display:none}
.diagram-urine-formation{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/urine-formation-png-efc756e7ea12.webp"))}













.diagram-photosynthesis{background-image:var(--thumbnail-load,url("/static/model-thumbnails/plant-photosynthesis.svg"))}
.diagram-photosynthesis{background-color:#263c31;background-image:url("/static/model-thumbnails/photosynthesis-refined.png");background-size:cover;background-position:center}
.diagram-photosynthesis .part{display:none}
.diagram-photosynthesis{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/photosynthesis-refined-png-465ec55b443e.webp"))}

.diagram-digestion-absorption{background-image:var(--thumbnail-load,url("/static/model-thumbnails/human-digestion-absorption.svg"))}
.diagram-digestion-absorption{background-color:#2e3430;background-image:url("/static/model-thumbnails/digestion-absorption-refined.png");background-size:cover;background-position:center}
.diagram-digestion-absorption .part{display:none}
.diagram-digestion-absorption{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/digestion-absorption-refined-png-b74ddbccb300.webp"))}







.diagram-heart-circulation-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/heart-circulation-3d.png?v=20260913"))!important;background-size:cover!important;background-position:center!important}
.diagram-heart-circulation-3d .part{display:none!important}
.diagram-heart-circulation-3d{background-color:#29352f;background-image:url("/static/model-thumbnails/heart-circulation-refined.png")!important;background-size:cover;background-position:center}
.diagram-heart-circulation-3d .part{display:none}
.diagram-heart-circulation-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/heart-circulation-refined-png-2272765d3cd4.webp"))!important}

.diagram-cell-microscope-studio{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cell-microscope-studio.png?v=20260919a"));background-size:cover;background-position:center}
.diagram-cell-microscope-studio .part{display:none}
.diagram-cell-microscope-studio{background-color:#25332f;background-image:url("/static/model-thumbnails/cell-microscope-studio-refined.png")!important;background-size:cover;background-position:center}
.diagram-cell-microscope-studio .part{display:none}
.diagram-cell-microscope-studio{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/cell-microscope-studio-refined-png-3716fb806b74.webp"))!important}

.diagram-roller-coaster-energy-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/roller-coaster-energy-3d-png-9018a7abf2f2.webp"));background-size:contain;background-position:center;background-color:#182831;}

.diagram-work-energy-theorem-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/work-energy-theorem-3d-png-95559fa26fa5.webp"));background-size:contain;background-position:center;background-color:#182831;}

.diagram-work-angle-projection-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/work-angle-projection-3d-png-db40c4a7783d.webp"));background-size:contain;background-position:center;background-color:#182831;}

.diagram-gravity-work-potential-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/gravity-work-potential-3d-png-fcc2e11c340c.webp"));background-size:contain;background-position:center;background-color:#182831;}

.diagram-spring-work-energy-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/spring-work-energy-3d-png-ca5cd8db0921.webp"));background-size:contain;background-position:center;background-color:#182831;}

.diagram-relativity-simultaneity-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/relativity-simultaneity.png"))!important;background-size:cover!important;background-position:center!important}
.diagram-relativity-simultaneity-lab .part{display:none}
.diagram-relativity-simultaneity-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/relativity-simultaneity-png-b16a1d58d0ff.webp"))!important}

.diagram-light-clock-time-dilation{background-image:var(--thumbnail-load,url("/static/model-thumbnails/light-clock-time-dilation.png"))!important;background-size:cover!important;background-position:center!important}
.diagram-light-clock-time-dilation .part{display:none}
.diagram-light-clock-time-dilation{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/light-clock-time-dilation-png-152aa613dca0.webp"))!important}

.diagram-relativistic-length-measurement{background-image:var(--thumbnail-load,url("/static/model-thumbnails/relativistic-length-measurement.png"))!important;background-size:cover!important;background-position:center!important}
.diagram-relativistic-length-measurement .part{display:none}
.diagram-relativistic-length-measurement{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/relativistic-length-measurement-png-b9c9a9b5d0db.webp"))!important}

.diagram-spacetime-gravitational-lens{background-image:var(--thumbnail-load,url("/static/model-thumbnails/spacetime-gravitational-lens.png"))!important;background-size:cover!important;background-position:center!important}
.diagram-spacetime-gravitational-lens .part{display:none}
.diagram-spacetime-gravitational-lens{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/spacetime-gravitational-lens-png-e5bbe8f8e5de.webp"))!important}

.diagram-expanding-universe-evidence{background-image:var(--thumbnail-load,url("/static/model-thumbnails/expanding-universe-evidence.png"))!important;background-size:cover!important;background-position:center!important}
.diagram-expanding-universe-evidence .part{display:none}
.diagram-expanding-universe-evidence{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/expanding-universe-evidence-png-6171fd6a1a2a.webp"))!important}

.diagram-newtonian-mechanics-limits{background-image:var(--thumbnail-load,url("/static/model-thumbnails/newtonian-mechanics-limits.png"))!important;background-size:cover!important;background-position:center!important}
.diagram-newtonian-mechanics-limits .part{display:none}
.diagram-newtonian-mechanics-limits{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/newtonian-mechanics-limits-png-aeaf42966f41.webp"))!important}

.diagram-stellar-life-cycle-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/stellar-life-cycle-lab.png"))!important;background-size:cover!important;background-position:center!important}
.diagram-stellar-life-cycle-lab .part{display:none}
.diagram-stellar-life-cycle-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/stellar-life-cycle-lab-png-3e348f240c11.webp"))!important}

.geography-lesson-links{display:grid;grid-template-columns:1fr 1fr;gap:8px;padding:0 18px 14px}.geography-lesson-links a{display:flex;min-height:44px;align-items:center;justify-content:center;padding:6px;border:1px solid #a4c8da;border-radius:8px;color:#165875;background:#eff8fc;font-size:16px;text-decoration:none}.geography-lesson-links a:hover{background:#d9eff8}.geography-lesson-links a[hidden]{display:none}
.diagram-contour-terrain-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/contour-terrain-lab-jpg-7edca6901141.webp"));background-size:cover;background-position:center}

.diagram-tray-balance-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/tray-balance-3d.png"));background-size:cover;background-position:center}
.diagram-tray-balance-3d .part{display:none}
.diagram-tray-balance-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/tray-balance-3d-png-82b876321fdd.webp"))}

.diagram-density-mass-volume{background-image:var(--thumbnail-load,url("/static/model-thumbnails/density-mass-volume.png"));background-size:cover;background-position:center}
.diagram-density-mass-volume .part{display:none}
.diagram-density-mass-volume{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/density-mass-volume-png-a88aeaa8fa1e.webp"))}

.diagram-liquid-density-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/liquid-density-3d.png"));background-size:cover;background-position:center}
.diagram-liquid-density-3d .part{display:none}
.diagram-liquid-density-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/liquid-density-3d-png-e754e89a85d6.webp"))}

.diagram-solid-density-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/solid-density-3d.png"));background-size:cover;background-position:center}
.diagram-solid-density-3d .part{display:none}
.diagram-solid-density-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/solid-density-3d-png-d65d7f45aef2.webp"))}

.diagram-density-material-detective{background-image:var(--thumbnail-load,url("/static/model-thumbnails/density-material-detective.png"));background-size:cover;background-position:center}
.diagram-density-material-detective .part{display:none}
.diagram-density-material-detective{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/density-material-detective-png-8fa273119682.webp"))}

.diagram-water-density-freezing{background-image:var(--thumbnail-load,url("/static/model-thumbnails/water-density-freezing.png"));background-size:cover;background-position:center}
.diagram-water-density-freezing .part{display:none}
.diagram-water-density-freezing{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/water-density-freezing-png-5c5b38af11d7.webp"))}

.diagram-monsoon-rainbelt-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/monsoon-rainbelt-lab-jpg-20c2fcf82781.webp"));background-size:cover;background-position:center}

.diagram-climate-landscape-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/climate-landscape-lab-jpg-9cb17a79ed5b.webp"));background-size:cover;background-position:center}

.diagram-orographic-rain-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/orographic-rain-lab-jpg-56b3d2a75ae7.webp"));background-size:cover;background-position:center}

.diagram-china-terrain-rivers-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/china-terrain-rivers-lab-jpg-d07bd800682e.webp"));background-size:cover;background-position:center}

.diagram-china-four-regions-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/china-four-regions-lab-jpg-17ef9891c893.webp"));background-size:cover;background-position:center}

.diagram-coulomb-law-3d{background-image:url("/static/model-thumbnails/coulomb-law-3d.png");background-size:cover;background-position:center}
.diagram-coulomb-law-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/coulomb-law-3d-png-262c3dc850f1.webp"))}
.diagram-coulomb-law-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/coulomb-law-3d-png-91599ca19558.webp"))}

.diagram-electric-field-ratio-3d{background-image:url("/static/model-thumbnails/electric-field-ratio-3d.png");background-size:cover;background-position:center}
.diagram-electric-field-ratio-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/electric-field-ratio-3d-png-38dcb0d961d3.webp"))}

.diagram-field-equipotential{background-image:var(--thumbnail-load,url("/static/model-thumbnails/electric-field-lines-equipotential.svg"))}

.diagram-electric-work-potential-3d{background-image:url("/static/model-thumbnails/electric-work-potential-3d.png");background-size:cover;background-position:center}
.diagram-electric-work-potential-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/electric-work-potential-3d-png-5df7c9159f87.webp"))}

.diagram-electric-voltage-projection-3d{background-image:url("/static/model-thumbnails/electric-voltage-projection-3d.png");background-size:cover;background-position:center}
.diagram-electric-voltage-projection-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/electric-voltage-projection-3d-png-3f175ab7203f.webp"))}

.diagram-electroscope{background-image:var(--thumbnail-load,url("/static/model-thumbnails/electroscope.png"));background-size:cover;background-position:center}
.diagram-electroscope .part{display:none}
.diagram-electroscope{background-image:var(--thumbnail-load,url("/static/model-thumbnails/electroscope-ch1.png"));background-size:cover;background-position:center}
.diagram-electroscope{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/electroscope-png-d70e5176cdb5.webp"))}
.diagram-electroscope{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/electroscope-ch1-png-fe6070d09e74.webp"))}

.diagram-capacitor-structure-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/capacitor-structure-3d.png"))!important;background-size:cover!important;background-position:center!important}
.diagram-capacitor-structure-3d .part{display:none}
.diagram-capacitor-structure-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/capacitor-structure-3d-png-4141e4c96ff2.webp"))!important}

.diagram-capacitor-charge{background-image:var(--thumbnail-load,url("/static/model-thumbnails/capacitor-charge-discharge.svg"))}
.diagram-capacitor-charge{background-image:var(--thumbnail-load,url("/static/model-thumbnails/capacitor-charge-discharge-v2.png"))}
.diagram-capacitor-charge{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/capacitor-charge-discharge-v2-png-9c08706ca203.webp"))}

.diagram-particle-electric{background-image:var(--thumbnail-load,url("/static/model-thumbnails/charged-particle-electric-field.svg"))}
.diagram-particle-electric{background-image:var(--thumbnail-load,url("/static/model-thumbnails/charged-particle-electric-field-v2.png"))}
.diagram-particle-electric{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/charged-particle-electric-field-v2-png-90c6b9d1663e.webp"))}

.diagram-oscilloscope-tube-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/oscilloscope-tube-3d.png"))}
.diagram-oscilloscope-tube-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/oscilloscope-tube-3d-png-1ec92f7e5d5d.webp"))}

.diagram-electrostatic-applications-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/electrostatic-applications-3d.png"))}
.diagram-electrostatic-applications-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/electrostatic-applications-3d-png-2a66fe0f97cb.webp"))}

.diagram-electrostatic-protection-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/electrostatic-protection-3d.png"))}
.diagram-electrostatic-protection-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/electrostatic-protection-3d-png-6e43c3cd5dac.webp"))}

.diagram-conductor-iu-characteristics{background-image:var(--thumbnail-load,url("/static/model-thumbnails/conductor-iu-characteristics.png"));background-size:cover;background-position:center}
.diagram-conductor-iu-characteristics .part{display:none}
.diagram-conductor-iu-characteristics{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/conductor-iu-characteristics-png-912cf61b62c1.webp"))}

.diagram-metal-wire-resistivity{background-image:var(--thumbnail-load,url("/static/model-thumbnails/metal-wire-resistivity.png"));background-size:cover;background-position:center}
.diagram-metal-wire-resistivity .part{display:none}
.diagram-metal-wire-resistivity{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/metal-wire-resistivity-png-cd0c7f75dff6.webp"))}

.diagram-resistance-factors{background-image:var(--thumbnail-load,url("/static/model-thumbnails/resistance-factors.png"));background-size:cover;background-position:center}
.diagram-resistance-factors .part{display:none}
.diagram-resistance-factors{background-image:var(--thumbnail-load,url("/static/model-thumbnails/resistance-factors-senior.png"));background-size:cover;background-position:center}
.diagram-resistance-factors .part{display:none}
.diagram-resistance-factors{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/resistance-factors-png-63f2ea5adfda.webp"))}
.diagram-resistance-factors{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/resistance-factors-senior-png-07c25b0f3ff2.webp"))}

.diagram-meter-conversion-calibration{background-image:var(--thumbnail-load,url("/static/model-thumbnails/meter-conversion-calibration.png"));background-size:cover;background-position:center}
.diagram-meter-conversion-calibration .part{display:none}
.diagram-meter-conversion-calibration{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/meter-conversion-calibration-png-af3e0de33ab4.webp"))}

.diagram-series-parallel-equivalence{background-image:var(--thumbnail-load,url("/static/model-thumbnails/series-parallel-equivalence.png"));background-size:cover;background-position:center}
.diagram-series-parallel-equivalence .part{display:none}
.diagram-series-parallel-equivalence{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/series-parallel-equivalence-png-3110e0e68f76.webp"))}

.diagram-current-microscopic{background-image:var(--thumbnail-load,url("/static/model-thumbnails/current-microscopic.png"));background-size:cover;background-position:center}
.diagram-current-microscopic .part{display:none}
.diagram-current-microscopic{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/current-microscopic-png-d7e6cd733c53.webp"))}

.diagram-closed-circuit-source-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/closed-circuit-source-3d.png"));background-size:cover;background-position:center}
.diagram-closed-circuit-source-3d .part { display: none; }
.diagram-closed-circuit-source-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/closed-circuit-source-3d.png"));background-size:cover;background-position:center}
.diagram-closed-circuit-source-3d .part{display:none}
.diagram-closed-circuit-source-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/closed-circuit-source-3d-png-e755fb315341.webp"))}
.diagram-closed-circuit-source-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/closed-circuit-source-3d-png-e755fb315341.webp"))}

.diagram-emf-internal-resistance-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/emf-internal-resistance-3d.png"));background-size:cover;background-position:center}
.diagram-emf-internal-resistance-3d .part{display:none}
.diagram-emf-internal-resistance-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/emf-internal-resistance-3d-png-9119755cc3b5.webp"))}

.diagram-multimeter-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/multimeter-3d.png"));background-size:cover;background-position:center}
.diagram-multimeter-3d .part{display:none}
.diagram-multimeter-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/multimeter-3d-png-74aafdcc67ab.webp"))}

.diagram-dynamic-circuit{background-image:var(--thumbnail-load,url("/static/model-thumbnails/dynamic-circuit-analysis.svg"))}
.diagram-dynamic-circuit{background-image:var(--thumbnail-load,url("/static/model-thumbnails/dynamic-circuit-analysis-v2.png"));background-size:cover;background-position:center}
.diagram-dynamic-circuit .part{display:none}
.diagram-dynamic-circuit{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/dynamic-circuit-analysis-v2-png-fc77cd96f996.webp"))}

.diagram-circuit-components-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/circuit-components-3d.png"));background-size:cover;background-position:center}
.diagram-circuit-components-3d .part{display:none}
.diagram-circuit-components-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/circuit-components-3d-png-1553ab5fbac5.webp"))}

.diagram-household{background-image:var(--thumbnail-load,url("/static/model-thumbnails/household-3d.png"))}
.diagram-household{background-image:var(--thumbnail-load,url("/static/model-thumbnails/household-senior.png"));background-size:cover;background-position:center}
.diagram-household .part{display:none}
.diagram-household{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/household-senior-png-ed16d3f59396.webp"))}
.diagram-household{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/household-3d-png-02c8c76f8b03.webp"))}

.diagram-magnetic-field-3d{background-image:url("/static/model-thumbnails/magnetic-field.png");background-size:cover;background-position:center}
.diagram-magnetic-field-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/magnetic-field-png-113767b045db.webp"))}




.diagram-magnetic-flux-3d{background-image:url("/static/model-thumbnails/magnetic-flux.png");background-size:cover;background-position:center}
.diagram-magnetic-flux-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/magnetic-flux-png-426021e9639b.webp"))}








.diagram-electromagnetic-wave-applications{background-image:url("/static/model-thumbnails/em-applications.png");background-size:cover;background-position:center}
.diagram-electromagnetic-wave-applications{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/em-applications-png-7074ea5922fa.webp"))}

.diagram-photoelectric{background-image:var(--thumbnail-load,url("/static/model-thumbnails/photoelectric-effect.svg"))}
.diagram-photoelectric{background-image:url("/static/model-thumbnails/photoelectric-chapter.png");background-size:cover;background-position:center}
.diagram-photoelectric{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/photoelectric-chapter-png-bc7a806bf720.webp"))}

.diagram-atomic-transition{background-image:var(--thumbnail-load,url("/static/model-thumbnails/atomic-energy-level-transition.svg"))}
.diagram-atomic-transition{background-image:url("/static/model-thumbnails/atomic-chapter.png");background-size:cover;background-position:center}
.diagram-atomic-transition{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/atomic-chapter-png-b030b93d2dfe.webp"))}

.diagram-electric-circuit-energy-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/electric-circuit-energy-3d-ch5-png-ad49a10c60ea.webp"))}

.diagram-joule-heating{background-image:var(--thumbnail-load,url("/static/model-thumbnails/joule-heating.png"));background-size:cover;background-position:center}
.diagram-joule-heating .part{display:none}
.diagram-joule-heating{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/joule-heating-ch5-png-e5cace6331d6.webp"))}
.diagram-joule-heating{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/joule-heating-png-452ed816f185.webp"))}

.diagram-pumped-storage-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/pumped-storage-3d-ch5-png-ee1201b162c7.webp"))}

.diagram-energy-resources-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/energy-resources-3d-ch5-png-1f02102e02a6.webp"))}

.diagram-energy-transformation-conservation{background-image:var(--thumbnail-load,url("/static/model-thumbnails/energy-transformation-conservation.png"));background-size:cover;background-position:center}
.diagram-energy-transformation-conservation .part{display:none}
.diagram-energy-transformation-conservation{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/energy-transformation-conservation-ch5-png-4d85d62a18f0.webp"))}
.diagram-energy-transformation-conservation{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/energy-transformation-conservation-png-fa454a0b8282.webp"))}

.diagram-household-energy{background-image:var(--thumbnail-load,url("/static/model-thumbnails/household-energy.png"));background-size:cover;background-position:center}
.diagram-household-energy .part{display:none}
.diagram-household-energy{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/household-energy-ch5-png-a114e12c9450.webp"))}
.diagram-household-energy{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/household-energy-png-2fdc529b062c.webp"))}

.diagram-pendulum-gravity-3d{background-image:url("/static/model-thumbnails/pendulum-gravity.png");background-size:cover;background-position:center}
.diagram-pendulum-gravity-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/pendulum-gravity-png-f749409e725a.webp"))}

.diagram-impulse-momentum-3d{background-image:url("/static/model-thumbnails/impulse-momentum.png");background-size:cover;background-position:center}
.diagram-impulse-momentum-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/impulse-momentum-png-41fe14f485e4.webp"))}

.diagram-momentum{background-image:var(--thumbnail-load,url("/static/model-thumbnails/collision-momentum.svg"))}
.diagram-momentum{background-image:url("/static/model-thumbnails/collision-momentum-v2.png");background-size:cover;background-position:center}
.diagram-momentum{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/collision-momentum-v2-png-a60ed36b5215.webp"))}

.diagram-refraction-pin-method-3d{background-image:url("/static/model-thumbnails/refraction-pins.png");background-size:cover;background-position:center}
.diagram-refraction-pin-method-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/refraction-pins-png-70ab8734317e.webp"))}

.diagram-double-slit-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/double-slit-3d.png"));background-size:cover;background-position:center}
.diagram-double-slit-3d .part{display:none}
.diagram-double-slit-3d{background-image:url("/static/model-thumbnails/double-slit-measurement.png");background-size:cover;background-position:center}
.diagram-double-slit-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/double-slit-measurement-png-5d2f4cef2c89.webp"))}
.diagram-double-slit-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/double-slit-3d-png-5657280bd042.webp"))}

.diagram-wave-snapshot-history{background-image:url("/static/model-thumbnails/wave-history.png");background-size:cover;background-position:center}
.diagram-wave-snapshot-history{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/wave-history-png-341aa2a456a3.webp"))}

.diagram-recoil-system-3d{background-image:url("/static/model-thumbnails/recoil-system.png");background-size:cover;background-position:center}
.diagram-recoil-system-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/recoil-system-png-5af339bddc37.webp"))}

.diagram-spring-oscillator-studio{background-image:var(--thumbnail-load,url("/static/model-thumbnails/spring-oscillator-studio.png"));background-size:cover;background-position:center}
.diagram-spring-oscillator-studio .part{display:none}
.diagram-spring-oscillator-studio{background-image:url("/static/model-thumbnails/spring-time-graphs.png");background-size:cover;background-position:center}
.diagram-spring-oscillator-studio{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/spring-time-graphs-png-9a2e6bc249c3.webp"))}
.diagram-spring-oscillator-studio{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/spring-oscillator-studio-png-d3246ae776ad.webp"))}

.diagram-forced-resonance-3d{background-image:url("/static/model-thumbnails/forced-resonance.png");background-size:cover;background-position:center}
.diagram-forced-resonance-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/forced-resonance-png-af7f5222193b.webp"))}

.diagram-mechanical-wave{background-image:var(--thumbnail-load,url("/static/model-thumbnails/mechanical-wave.svg"))}
.diagram-mechanical-wave{background-image:url("/static/model-thumbnails/mechanical-wave-v2.png");background-size:cover;background-position:center}
.diagram-mechanical-wave{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/mechanical-wave-v2-png-d3dc01ff31ce.webp"))}

.diagram-wave-phenomena{background-image:var(--thumbnail-load,url("/static/model-thumbnails/wave-phenomena.svg"))}
.diagram-wave-phenomena{background-image:url("/static/model-thumbnails/water-tank-v2.png");background-size:cover;background-position:center}
.diagram-wave-phenomena{background-image:url("/static/model-thumbnails/water-tank-v2.png");background-size:cover;background-position:center}
.diagram-wave-phenomena{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/water-tank-v2-png-4c27080db3b6.webp"))}
.diagram-wave-phenomena{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/water-tank-v2-png-4c27080db3b6.webp"))}

.diagram-doppler-wavefront-lab{background-image:url("/static/model-thumbnails/doppler-wavefront.png");background-size:cover;background-position:center}
.diagram-doppler-wavefront-lab{background-image:url("/static/model-thumbnails/doppler-wavefront.png");background-size:cover;background-position:center}
.diagram-doppler-wavefront-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/doppler-wavefront-png-9f3a6888194b.webp"))}
.diagram-doppler-wavefront-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/doppler-wavefront-png-9f3a6888194b.webp"))}

.diagram-refraction-law-3d{background-image:url("/static/model-thumbnails/refraction-law.png");background-size:cover;background-position:center}
.diagram-refraction-law-3d{background-image:url("/static/model-thumbnails/refraction-law.png");background-size:cover;background-position:center}
.diagram-refraction-law-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/refraction-law-png-76be3c386523.webp"))}
.diagram-refraction-law-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/refraction-law-png-76be3c386523.webp"))}

.diagram-total-reflection-fiber-3d{background-image:url("/static/model-thumbnails/tir-fiber.png");background-size:cover;background-position:center}
.diagram-total-reflection-fiber-3d{background-image:url("/static/model-thumbnails/tir-fiber.png");background-size:cover;background-position:center}
.diagram-total-reflection-fiber-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/tir-fiber-png-1f7f9ec0b0a8.webp"))}
.diagram-total-reflection-fiber-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/tir-fiber-png-1f7f9ec0b0a8.webp"))}

.diagram-light-diffraction-3d{background-image:url("/static/model-thumbnails/diffraction.png");background-size:cover;background-position:center}
.diagram-light-diffraction-3d{background-image:url("/static/model-thumbnails/diffraction.png");background-size:cover;background-position:center}
.diagram-light-diffraction-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/diffraction-png-b0031e699520.webp"))}
.diagram-light-diffraction-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/diffraction-png-b0031e699520.webp"))}

.diagram-polarization-3d{background-image:url("/static/model-thumbnails/polarization.png");background-size:cover;background-position:center}
.diagram-polarization-3d{background-image:url("/static/model-thumbnails/polarization.png");background-size:cover;background-position:center}
.diagram-polarization-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/polarization-png-5359f960b568.webp"))}
.diagram-polarization-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/polarization-png-5359f960b568.webp"))}

.diagram-laser-properties-3d{background-image:url("/static/model-thumbnails/laser-properties.png");background-size:cover;background-position:center}
.diagram-laser-properties-3d{background-image:url("/static/model-thumbnails/laser-properties.png");background-size:cover;background-position:center}
.diagram-laser-properties-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/laser-properties-png-dc1eeecfb847.webp"))}
.diagram-laser-properties-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/laser-properties-png-dc1eeecfb847.webp"))}






.diagram-charged-magnetic{background-image:var(--thumbnail-load,url("/static/model-thumbnails/charged-particle-magnetic-field.png"))}
.diagram-charged-magnetic{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/charged-particle-magnetic-field-png-bfb5c2224b1b.webp"))}

.diagram-hall-effect{background-image:var(--thumbnail-load,url("/static/model-thumbnails/hall-effect.svg"))}

.diagram-velocity-selector-mass-spectrometer-3d { background: url("/static/model-thumbnails/velocity-selector-mass-spectrometer-3d.png") center / cover no-repeat; }
.diagram-velocity-selector-mass-spectrometer-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/velocity-selector-mass-spectrometer-3d-png-fcf205cff108.webp"))}

.diagram-electromagnetic-induction{background-image:var(--thumbnail-load,url("/static/model-thumbnails/electromagnetic-induction.png"))}
.diagram-electromagnetic-induction{background-image:url("/static/model-thumbnails/induction-chapter.png");background-size:cover;background-position:center}
.diagram-electromagnetic-induction{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/induction-chapter-png-b79f8209679b.webp"))}
.diagram-electromagnetic-induction{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/electromagnetic-induction-png-929331b5e539.webp"))}

.diagram-conducting-rod-energy-3d { background: url("/static/model-thumbnails/conducting-rod-energy-3d.png") center / cover no-repeat; }
.diagram-conducting-rod-energy-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/conducting-rod-energy-3d-png-13683f3b307f.webp"))}

.diagram-self-mutual-inductance-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/self-mutual-inductance-3d.png"));background-size:cover;background-position:center}
.diagram-self-mutual-inductance-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/self-mutual-inductance-3d-png-1796f4d28d07.webp"))}

.diagram-eddy-current-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/eddy-current-3d.png"));background-size:cover;background-position:center}
.diagram-eddy-current-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/eddy-current-3d-png-0e4ee73fc9c1.webp"))}

.diagram-ac-generator-rms-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/ac-generator-rms-3d.png"));background-size:cover;background-position:center}
.diagram-ac-generator-rms-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/ac-generator-rms-3d-png-d9118a70ca2f.webp"))}

.diagram-ac-transformer{background-image:var(--thumbnail-load,url("/static/model-thumbnails/alternating-current-transformer.svg"))}
.diagram-ac-transformer{background-image:var(--thumbnail-load,url("/static/model-thumbnails/alternating-current-transformer.png"));background-size:cover;background-position:center}
.diagram-ac-transformer{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/alternating-current-transformer-png-ae01d7d19a95.webp"))}

.diagram-power-transmission-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/power-transmission-3d.png"));background-size:cover;background-position:center}
.diagram-power-transmission-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/power-transmission-3d-png-327a0a616419.webp"))}

.diagram-lc-oscillation-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/lc-oscillation-3d.png"));background-size:cover;background-position:center}
.diagram-lc-oscillation-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/lc-oscillation-3d-png-effe744cf805.webp"))}

.diagram-electromagnetic-wave-3d{background-image:url("/static/model-thumbnails/em-wave.png");background-size:cover;background-position:center}
.diagram-electromagnetic-wave-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/em-wave-png-f699c2f12cb5.webp"))}

.diagram-sensor-principles-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/sensor-principles-3d.png"));background-size:cover;background-position:center}
.diagram-sensor-principles-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/sensor-principles-3d-png-d1e71e463db7.webp"))}

.diagram-sensor-automatic-control{background-image:var(--thumbnail-load,url("/static/model-thumbnails/sensor-automatic-control.png"));background-size:cover;background-position:center}
.diagram-sensor-automatic-control{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/sensor-automatic-control-png-a98e2c91c5f4.webp"))}

.diagram-oil-film-molecule-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/oil-film-molecule-lab.png"));background-size:cover;background-position:center}
.diagram-oil-film-molecule-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/oil-film-molecule-lab-png-985ff6dc9ec8.webp"))}

.diagram-gas-speed-pressure-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/gas-speed-pressure-3d.png"));background-size:cover;background-position:center}
.diagram-gas-speed-pressure-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/gas-speed-pressure-3d-png-6f04a990a2fc.webp"))}

.diagram-brownian-motion{background-image:var(--thumbnail-load,url("/static/model-thumbnails/brownian-molecular-motion.svg"))}
.diagram-brownian-motion{background-image:var(--thumbnail-load,url("/static/model-thumbnails/brownian-molecular-motion.png"));background-size:cover;background-position:center}
.diagram-brownian-motion{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/brownian-molecular-motion-png-fb64b8cbfbb7.webp"))}

.diagram-gas-laws{background-image:var(--thumbnail-load,url("/static/model-thumbnails/gas-experimental-laws.svg"))}
.diagram-gas-laws{background-image:var(--thumbnail-load,url("/static/model-thumbnails/gas-experimental-laws.png"))}
.diagram-gas-laws{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/gas-experimental-laws-png-0d20d593cf02.webp"))}

.diagram-surface-tension-capillary-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/surface-tension-capillary-3d.png"));background-size:cover;background-position:center}
.diagram-surface-tension-capillary-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/surface-tension-capillary-3d-png-e3f67f04c065.webp"))}

.diagram-crystal-materials-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/crystal-materials-3d.png"));background-size:cover;background-position:center}
.diagram-crystal-materials-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/crystal-materials-3d-png-52a6818796fe.webp"))}

.diagram-liquid-crystal-display-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/liquid-crystal-display-3d.png"));background-size:cover;background-position:center}
.diagram-liquid-crystal-display-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/liquid-crystal-display-3d-png-99b4754ccdb1.webp"))}

.diagram-thermodynamics-first-law{background-image:var(--thumbnail-load,url("/static/model-thumbnails/thermodynamics-first-law.png"))}
.diagram-thermodynamics-first-law{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/thermodynamics-first-law-png-34787b0a15d2.webp"))}

.diagram-thermodynamics-second-law-3d { background: url("/static/model-thumbnails/thermodynamics-second-law-3d.png") center / cover no-repeat; }
.diagram-thermodynamics-second-law-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/thermodynamics-second-law-3d-png-820d629a39bb.webp"))}

.diagram-matter-wave-uncertainty-3d{background: url("/static/model-thumbnails/matter-wave-uncertainty-3d.png") center / cover no-repeat;}
.diagram-matter-wave-uncertainty-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/matter-wave-uncertainty-3d-png-cf2050056577.webp"))}

.diagram-rutherford-scattering-3d{background:url("/static/model-thumbnails/rutherford-scattering-3d.png") center / cover no-repeat;}
.diagram-rutherford-scattering-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/rutherford-scattering-3d-png-1561e4fb8ab9.webp"))}

.diagram-nuclear-decay{background-image:var(--thumbnail-load,url("/static/model-thumbnails/radioactive-decay-nuclear-reaction.png"))}
.diagram-nuclear-decay{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/radioactive-decay-nuclear-reaction-png-4b1f011b23e0.webp"))}

.diagram-nuclear-binding-energy{background:url("/static/model-thumbnails/nuclear-binding-energy.png") center / cover no-repeat;}
.diagram-nuclear-binding-energy{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/nuclear-binding-energy-png-2b9c7582b799.webp"))}

.diagram-nuclear-energy-devices-3d{background:url("/static/model-thumbnails/nuclear-energy-devices-3d.png") center / cover no-repeat;}
.diagram-nuclear-energy-devices-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/nuclear-energy-devices-3d-png-913a7c90de46.webp"))}

.diagram-magnetic-induction-strength-3d{background-image:url("/static/model-thumbnails/magnetic-strength.png");background-size:cover;background-position:center}
.diagram-magnetic-induction-strength-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/magnetic-strength-png-844ca897e036.webp"))}




.diagram-textbook-tray-balance-2d{background-color:#fffefa;background-image:var(--thumbnail-load,url("/static/model-thumbnails/textbook-tray-balance-2d.svg"));background-size:contain;background-position:center;background-repeat:no-repeat}
.diagram-textbook-tray-balance-2d .part{display:none}

.diagram-electric-workbench{background-image:var(--thumbnail-load,url("/static/model-thumbnails/electric-workbench.png"));background-size:cover;background-position:center}
.diagram-electric-workbench{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/electric-workbench-png-42bee4230422.webp"))}













.diagram-ruler-measurement{background-image:var(--thumbnail-load,url("/static/model-thumbnails/ruler-measurement.svg?v=20261008"))}

.diagram-stopwatch-time{background-image:var(--thumbnail-load,url("/static/model-thumbnails/stopwatch-time.svg?v=20261008"));}

.diagram-which-train-moves{background-image:var(--thumbnail-load,url("/static/model-thumbnails/which-train-moves.png"));}
.diagram-which-train-moves{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/which-train-moves-png-2bbc34d1ef60.webp"))}



.diagram-incline-speed-measurement{background-image:var(--thumbnail-load,url("/static/model-thumbnails/incline-speed-measurement.svg?v=20261008"));}

.diagram-average-speed-mean{background-image:var(--thumbnail-load,url("/static/model-thumbnails/average-speed-mean.svg?v=20261009"));}

.diagram-mechanical-motion-review{background-image:var(--thumbnail-load,url("/static/model-thumbnails/mechanical-motion-review.svg?v=20261009"));}



.diagram-sound{background-image:var(--thumbnail-load,url("/static/model-thumbnails/sound-generation.svg?v=20261009"))}

.diagram-sound-classic{background-image:var(--thumbnail-load,url("/static/model-thumbnails/sound-classic.svg?v=20261009"))}

.diagram-sound-properties{background-image:var(--thumbnail-load,url("/static/model-thumbnails/sound-properties.svg?v=20261009"))}

.diagram-echo-ranging{background-image:var(--thumbnail-load,url("/static/model-thumbnails/echo-ranging.svg?v=20261009"))}

.diagram-sound-information-energy{background-image:var(--thumbnail-load,url("/static/model-thumbnails/sound-information-energy.svg?v=20261009"))}

.diagram-noise-control{background-image:var(--thumbnail-load,url("/static/model-thumbnails/noise-control.svg?v=20261009"))}

.diagram-soundproof-room{background-image:var(--thumbnail-load,url("/static/model-thumbnails/soundproof-room.svg?v=20261009"))}

.diagram-compare-car-speeds{background-image:var(--thumbnail-load,url("/static/model-thumbnails/compare-car-speeds.svg?v=20261009"));}

.diagram-primary-micro-explorer {background-image:var(--thumbnail-load, url('/static/model-thumbnails/primary-micro-explorer.svg?v=20261009')) !important;background-size:contain !important;background-position:center !important;background-repeat:no-repeat !important;background-color:#f4f3e5 !important;}
.diagram-primary-micro-explorer .part {display:none !important;}










.diagram-lens-focus-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/lens-focus-lab.svg?v=20261009b"));background-size:cover;background-position:center}
.diagram-lens-focus-lab .part{display:none}

.diagram-homemade-camera{background-image:var(--thumbnail-load,url("/static/model-thumbnails/homemade-camera.svg?v=20261009b"));background-size:cover;background-position:center}
.diagram-homemade-camera .part{display:none}

.diagram-homemade-thermometer{background-image:var(--thumbnail-load,url("/static/model-thumbnails/homemade-thermometer.svg?v=20261009b"));background-size:cover;background-position:center}
.diagram-homemade-thermometer .part{display:none}

.diagram-nobel-physics-2026{background-image:var(--thumbnail-load,url("/static/model-thumbnails/nobel-physics-2026.png"));background-size:cover;background-position:center;background-color:#080b16}
.diagram-nobel-physics-2026 .part{display:none}
.diagram-nobel-physics-2026{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/nobel-physics-2026-png-ede8dcfcd2d8.webp"))}

.diagram-iron-redox-evidence{background-image:var(--thumbnail-load,url("/static/model-thumbnails/iron-redox-evidence.svg?v=1"));background-size:cover;background-position:center}
.diagram-iron-redox-evidence .part{display:none}

.diagram-iron-hydroxide{background-image:var(--thumbnail-load,url("/static/model-thumbnails/iron-hydroxide.svg?v=1"));background-size:cover;background-position:center}
.diagram-iron-hydroxide .part{display:none}

.diagram-iron-oxides{background-image:var(--thumbnail-load,url("/static/model-thumbnails/iron-oxides.svg?v=1"));background-size:cover;background-position:center}
.diagram-iron-oxides .part{display:none}

.diagram-aluminum-film{background-image:var(--thumbnail-load,url("/static/model-thumbnails/aluminum-film.svg?v=1"));background-size:cover;background-position:center}
.diagram-aluminum-film .part{display:none}

.diagram-reaction-stoichiometry{background-image:var(--thumbnail-load,url("/static/model-thumbnails/reaction-stoichiometry.svg?v=1"));background-size:cover;background-position:center}
.diagram-reaction-stoichiometry .part{display:none}

.diagram-alloy-materials{background-image:var(--thumbnail-load,url("/static/model-thumbnails/alloy-materials.svg?v=1"));background-size:cover;background-position:center}
.diagram-alloy-materials .part{display:none}

.diagram-periodic-trends{background-image:var(--thumbnail-load,url("/static/model-thumbnails/periodic-trends.svg?v=1"));background-size:cover;background-position:center}
.diagram-periodic-trends .part{display:none}

.diagram-group-trends{background-image:var(--thumbnail-load,url("/static/model-thumbnails/group-trends.svg?v=1"));background-size:cover;background-position:center}
.diagram-group-trends .part{display:none}

.diagram-chemical-bonds{background-image:var(--thumbnail-load,url("/static/model-thumbnails/chemical-bonds.svg?v=1"));background-size:cover;background-position:center}
.diagram-chemical-bonds .part{display:none}

.diagram-bond-changes{background-image:var(--thumbnail-load,url("/static/model-thumbnails/bond-changes.svg?v=1"));background-size:cover;background-position:center}
.diagram-bond-changes .part{display:none}

.diagram-chemistry-ch2-review{background-image:var(--thumbnail-load,url("/static/model-thumbnails/chemistry-ch2-review.svg?v=1"));background-size:cover;background-position:center}
.diagram-chemistry-ch2-review .part{display:none}

.diagram-chemistry-ch3-review{background-image:var(--thumbnail-load,url("/static/model-thumbnails/chemistry-ch3-review.svg?v=1"));background-size:cover;background-position:center}
.diagram-chemistry-ch3-review .part{display:none}

.diagram-chemistry-ch4-review{background-image:var(--thumbnail-load,url("/static/model-thumbnails/chemistry-ch4-review.svg?v=1"));background-size:cover;background-position:center}
.diagram-chemistry-ch4-review .part{display:none}

.diagram-osmosis-plasmolysis-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/osmosis-plasmolysis-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-osmosis-plasmolysis-lab .part{display:none}

.diagram-membrane-transport-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/membrane-transport-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-membrane-transport-lab .part{display:none}

.diagram-mitosis-cycle-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/mitosis-cycle-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-mitosis-cycle-lab .part{display:none}

.diagram-protein-structure-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/protein-structure-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-protein-structure-lab .part{display:none}

.diagram-secretory-protein-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/secretory-protein-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-secretory-protein-lab .part{display:none}

.diagram-enzyme-exploration-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/enzyme-exploration-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-enzyme-exploration-lab .part{display:none}

.diagram-cellular-respiration-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cellular-respiration-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-cellular-respiration-lab .part{display:none}

.diagram-photosynthesis-process-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/photosynthesis-process-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-photosynthesis-process-lab .part{display:none}

.diagram-atp-energy-coupling-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/atp-energy-coupling-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-atp-energy-coupling-lab .part{display:none}

.diagram-cell-diversity-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cell-diversity-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-cell-diversity-lab .part{display:none}

.diagram-organic-detection-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/organic-detection-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-organic-detection-lab .part{display:none}

.diagram-dna-rna-builder-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/dna-rna-builder-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-dna-rna-builder-lab .part{display:none}

.diagram-eukaryotic-cell-3d-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/eukaryotic-cell-3d-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-eukaryotic-cell-3d-lab .part{display:none}

.diagram-yeast-respiration-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/yeast-respiration-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-yeast-respiration-lab .part{display:none}

.diagram-photosynthesis-factors-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/photosynthesis-factors-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-photosynthesis-factors-lab .part{display:none}

.diagram-cell-fate-aging-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cell-fate-aging-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-cell-fate-aging-lab .part{display:none}

.diagram-mendel-genetics-lab{background-color:#e5ecdb;background-image:var(--thumbnail-load,url("/static/model-thumbnails/mendel-genetics-lab.png"));background-size:contain;background-repeat:no-repeat;background-position:center}
.diagram-mendel-genetics-lab .part{display:none}
.diagram-mendel-genetics-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/mendel-genetics-lab-png-de407428a5ab.webp"))}

.diagram-meiosis-fertilization-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/meiosis-fertilization-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-meiosis-fertilization-lab .part{display:none}

.diagram-mitosis-meiosis-comparison{background-image:var(--thumbnail-load,url("/static/model-thumbnails/mitosis-meiosis-comparison.svg?v=1"));background-size:cover;background-position:center}
.diagram-mitosis-meiosis-comparison .part{display:none}

.diagram-sex-linked-inheritance-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/sex-linked-inheritance-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-sex-linked-inheritance-lab .part{display:none}

.diagram-genetic-material-evidence-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/genetic-material-evidence-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-genetic-material-evidence-lab .part{display:none}

.diagram-dna-structure-gene-map{background-image:var(--thumbnail-load,url("/static/model-thumbnails/dna-structure-gene-map.svg?v=1"));background-size:cover;background-position:center}
.diagram-dna-structure-gene-map .part{display:none}

.diagram-dna-replication-evidence{background-image:var(--thumbnail-load,url("/static/model-thumbnails/dna-replication-evidence.svg?v=1"));background-size:cover;background-position:center}
.diagram-dna-replication-evidence .part{display:none}

.diagram-transcription-rna-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/transcription-rna-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-transcription-rna-lab .part{display:none}

.diagram-translation-protein-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/translation-protein-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-translation-protein-lab .part{display:none}

.diagram-gene-expression-traits{background-image:var(--thumbnail-load,url("/static/model-thumbnails/gene-expression-traits.svg?v=1"));background-size:cover;background-position:center}
.diagram-gene-expression-traits .part{display:none}

.diagram-mutation-recombination-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/mutation-recombination-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-mutation-recombination-lab .part{display:none}

.diagram-chromosome-variation-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/chromosome-variation-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-chromosome-variation-lab .part{display:none}

.diagram-pedigree-inheritance-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/pedigree-inheritance-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-pedigree-inheritance-lab .part{display:none}

.diagram-common-ancestry-evidence{background-image:var(--thumbnail-load,url("/static/model-thumbnails/common-ancestry-evidence.svg?v=1"));background-size:cover;background-position:center}
.diagram-common-ancestry-evidence .part{display:none}

.diagram-natural-selection-frequency{background-image:var(--thumbnail-load,url("/static/model-thumbnails/natural-selection-frequency.svg?v=1"));background-size:cover;background-position:center}
.diagram-natural-selection-frequency .part{display:none}

.diagram-isolation-coevolution-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/isolation-coevolution-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-isolation-coevolution-lab .part{display:none}

.diagram-nobel-medicine-2026{background-image:var(--thumbnail-load,url("/static/model-thumbnails/nobel-medicine-2026.png"));background-size:cover;background-position:center;background-color:#080b16}
.diagram-nobel-medicine-2026 .part{display:none}
.diagram-nobel-medicine-2026{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/nobel-medicine-2026-png-3f86ca684a3d.webp"))}




.diagram-chapter2-motion-cinematic{background-image:var(--thumbnail-load,url("/static/model-thumbnails/chapter2-motion-cinematic.svg?v=2"));background-size:cover;background-position:center}
.diagram-chapter2-motion-cinematic .part{display:none}





.diagram-internal-environment-exchange-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/internal-environment-exchange-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-internal-environment-exchange-lab .part{display:none}

.diagram-ph-buffer-homeostasis-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/ph-buffer-homeostasis-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-ph-buffer-homeostasis-lab .part{display:none}

.diagram-neural-hierarchy-3d-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/neural-hierarchy-3d-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-neural-hierarchy-3d-lab .part{display:none}

.diagram-reflex-arc-investigation-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/reflex-arc-investigation-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-reflex-arc-investigation-lab .part{display:none}

.diagram-membrane-potential-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/membrane-potential-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-membrane-potential-lab .part{display:none}

.diagram-synapse-integration-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/synapse-integration-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-synapse-integration-lab .part{display:none}

.diagram-higher-brain-evidence-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/higher-brain-evidence-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-higher-brain-evidence-lab .part{display:none}

.diagram-endocrine-research-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/endocrine-research-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-endocrine-research-lab .part{display:none}

.diagram-hormone-feedback-axis-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/hormone-feedback-axis-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-hormone-feedback-axis-lab .part{display:none}

.diagram-glucose-homeostasis-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/glucose-homeostasis-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-glucose-homeostasis-lab .part{display:none}

.diagram-thermoregulation-balance-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/thermoregulation-balance-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-thermoregulation-balance-lab .part{display:none}

.diagram-water-salt-balance-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/water-salt-balance-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-water-salt-balance-lab .part{display:none}

.diagram-immune-defenses-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/immune-defenses-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-immune-defenses-lab .part{display:none}

.diagram-humoral-immunity-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/humoral-immunity-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-humoral-immunity-lab .part{display:none}

.diagram-cytotoxic-immunity-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cytotoxic-immunity-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-cytotoxic-immunity-lab .part{display:none}

.diagram-immune-memory-vaccine-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/immune-memory-vaccine-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-immune-memory-vaccine-lab .part{display:none}

.diagram-immune-dysregulation-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/immune-dysregulation-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-immune-dysregulation-lab .part{display:none}

.diagram-auxin-phototropism-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/auxin-phototropism-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-auxin-phototropism-lab .part{display:none}

.diagram-auxin-concentration-distribution-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/auxin-concentration-distribution-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-auxin-concentration-distribution-lab .part{display:none}

.diagram-plant-hormone-coordination-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/plant-hormone-coordination-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-plant-hormone-coordination-lab .part{display:none}

.diagram-plant-regulator-investigation-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/plant-regulator-investigation-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-plant-regulator-investigation-lab .part{display:none}

.diagram-plant-environment-signals-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/plant-environment-signals-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-plant-environment-signals-lab .part{display:none}

.diagram-sulfur-dioxide-lab { background: #efe8f8; }
.diagram-sulfur-dioxide-lab .part { display: none; }
.diagram-sulfur-dioxide-lab { background-image: var(--thumbnail-load, url("/static/model-thumbnails/sulfur-dioxide-lab.svg")); background-size: cover; background-position: center; }

.diagram-sulfuric-acid-lab { background: #f4efe6; }
.diagram-sulfuric-acid-lab .part { display: none; }
.diagram-sulfuric-acid-lab { background-image: var(--thumbnail-load, url("/static/model-thumbnails/sulfuric-acid-lab.svg")); background-size: cover; background-position: center; }

.diagram-sulfate-ion-test { background: #eaf3f7; }
.diagram-sulfate-ion-test .part { display: none; }
.diagram-sulfate-ion-test { background-image: var(--thumbnail-load, url("/static/model-thumbnails/sulfate-ion-test.svg")); background-size: cover; background-position: center; }

.diagram-sulfur-valence-lab { background: #f0ebf8; }
.diagram-sulfur-valence-lab .part { display: none; }
.diagram-sulfur-valence-lab { background-image: var(--thumbnail-load, url("/static/model-thumbnails/sulfur-valence-lab.svg")); background-size: cover; background-position: center; }

.diagram-nitrogen-oxides-lab { background: #eaf4f7; }
.diagram-nitrogen-oxides-lab .part { display: none; }
.diagram-nitrogen-oxides-lab { background-image: var(--thumbnail-load, url("/static/model-thumbnails/nitrogen-oxides-lab.svg")); background-size: cover; background-position: center; }

.diagram-ammonia-ammonium-lab { background: #f1eaf8; }
.diagram-ammonia-ammonium-lab .part { display: none; }
.diagram-ammonia-ammonium-lab { background-image: var(--thumbnail-load, url("/static/model-thumbnails/ammonia-ammonium-lab.svg")); background-size: cover; background-position: center; }

.diagram-nitric-acid-lab { background: #f6eee8; }
.diagram-nitric-acid-lab .part { display: none; }
.diagram-nitric-acid-lab { background-image: var(--thumbnail-load, url("/static/model-thumbnails/nitric-acid-lab.svg")); background-size: cover; background-position: center; }

.diagram-inorganic-materials-lab { background: #eee8f7; }
.diagram-inorganic-materials-lab .part { display: none; }
.diagram-inorganic-materials-lab { background-image: var(--thumbnail-load, url("/static/model-thumbnails/inorganic-materials-lab.svg")); background-size: cover; background-position: center; }

.diagram-salt-impurity-lab { background: #e2f3f0; }
.diagram-salt-impurity-lab .part { display: none; }
.diagram-salt-impurity-lab { background-image: var(--thumbnail-load, url("/static/model-thumbnails/salt-impurity-lab.svg")); background-size: cover; background-position: center; }

.diagram-reaction-heat-lab { background: #faf1e3; }
.diagram-reaction-heat-lab .part { display: none; }
.diagram-reaction-heat-lab { background-image: var(--thumbnail-load, url("/static/model-thumbnails/reaction-heat-lab.svg")); background-size: cover; background-position: center; }

.diagram-galvanic-cell-lab { background: #e5f0f3; }
.diagram-galvanic-cell-lab .part { display: none; }
.diagram-galvanic-cell-lab { background-image: var(--thumbnail-load, url("/static/model-thumbnails/galvanic-cell-lab.svg")); background-size: cover; background-position: center; }

.diagram-reaction-rate-lab { background: #edf0fa; }
.diagram-reaction-rate-lab .part { display: none; }
.diagram-reaction-rate-lab { background-image: var(--thumbnail-load, url("/static/model-thumbnails/reaction-rate-lab.svg")); background-size: cover; background-position: center; }

.diagram-reversible-reaction-lab { background: #eaf3ef; }
.diagram-reversible-reaction-lab .part { display: none; }
.diagram-reversible-reaction-lab { background-image: var(--thumbnail-load, url("/static/model-thumbnails/reversible-reaction-lab.svg")); background-size: cover; background-position: center; }

.diagram-carbon-skeleton-lab { background: #eaf0f7; }
.diagram-carbon-skeleton-lab .part { display: none; }
.diagram-carbon-skeleton-lab { background-image: var(--thumbnail-load, url("/static/model-thumbnails/carbon-skeleton-lab.svg")); background-size: cover; background-position: center; }

.diagram-ethene-addition-lab { background: #f5ede1; }
.diagram-ethene-addition-lab .part { display: none; }
.diagram-ethene-addition-lab { background-image: var(--thumbnail-load, url("/static/model-thumbnails/ethene-addition-lab.svg")); background-size: cover; background-position: center; }

.diagram-addition-polymer-lab { background: #eeedf7; }
.diagram-addition-polymer-lab .part { display: none; }
.diagram-addition-polymer-lab { background-image: var(--thumbnail-load, url("/static/model-thumbnails/addition-polymer-lab.svg")); background-size: cover; background-position: center; }

.diagram-ethanol-properties-lab { background: #f5eee5; }
.diagram-ethanol-properties-lab .part { display: none; }
.diagram-ethanol-properties-lab { background-image: var(--thumbnail-load, url("/static/model-thumbnails/ethanol-properties-lab.svg")); background-size: cover; background-position: center; }

.diagram-acetic-ester-lab { background: #e6f5ef; }
.diagram-acetic-ester-lab .part { display: none; }
.diagram-acetic-ester-lab { background-image: var(--thumbnail-load, url("/static/model-thumbnails/acetic-ester-lab.svg")); background-size: cover; background-position: center; }

.diagram-nutrient-lab { background: #e6f5ef; }
.diagram-nutrient-lab .part { display: none; }
.diagram-nutrient-lab { background-image: var(--thumbnail-load, url("/static/model-thumbnails/nutrient-lab.svg")); background-size: cover; background-position: center; }

.diagram-metal-resource-lab { background: #e8eff4; }
.diagram-metal-resource-lab .part { display: none; }
.diagram-metal-resource-lab { background-image: var(--thumbnail-load, url("/static/model-thumbnails/metal-resource-lab.svg")); background-size: cover; background-position: center; }

.diagram-seawater-resource-lab { background: #e5f3f4; }
.diagram-seawater-resource-lab .part { display: none; }
.diagram-seawater-resource-lab { background-image: var(--thumbnail-load, url("/static/model-thumbnails/seawater-resource-lab.svg")); background-size: cover; background-position: center; }

.diagram-fossil-resource-lab { background: #f0ede5; }
.diagram-fossil-resource-lab .part { display: none; }
.diagram-fossil-resource-lab { background-image: var(--thumbnail-load, url("/static/model-thumbnails/fossil-resource-lab.svg")); background-size: cover; background-position: center; }

.diagram-chemical-use-lab { background: #eef3e7; }
.diagram-chemical-use-lab .part { display: none; }
.diagram-chemical-use-lab { background-image: var(--thumbnail-load, url("/static/model-thumbnails/chemical-use-lab.svg")); background-size: cover; background-position: center; }

.diagram-green-chemistry-lab { background: #e8f2ef; }
.diagram-green-chemistry-lab .part { display: none; }
.diagram-green-chemistry-lab { background-image: var(--thumbnail-load, url("/static/model-thumbnails/green-chemistry-lab.svg")); background-size: cover; background-position: center; }

.diagram-chemistry-ch5-review { background: #e8f2ef; }
.diagram-chemistry-ch5-review .part { display: none; }
.diagram-chemistry-ch5-review { background-image: var(--thumbnail-load, url("/static/model-thumbnails/chemistry-ch5-review.svg")); background-size: cover; background-position: center; }

.diagram-chemistry-ch6-review { background: #e8f2ef; }
.diagram-chemistry-ch6-review .part { display: none; }
.diagram-chemistry-ch6-review { background-image: var(--thumbnail-load, url("/static/model-thumbnails/chemistry-ch6-review.svg")); background-size: cover; background-position: center; }

.diagram-chemistry-ch7-review { background: #e8f2ef; }
.diagram-chemistry-ch7-review .part { display: none; }
.diagram-chemistry-ch7-review { background-image: var(--thumbnail-load, url("/static/model-thumbnails/chemistry-ch7-review.svg")); background-size: cover; background-position: center; }

.diagram-chemistry-ch8-review { background: #e8f2ef; }
.diagram-chemistry-ch8-review .part { display: none; }
.diagram-chemistry-ch8-review { background-image: var(--thumbnail-load, url("/static/model-thumbnails/chemistry-ch8-review.svg")); background-size: cover; background-position: center; }

.diagram-population-growth-capacity{background-image:var(--thumbnail-load,url("/static/model-thumbnails/population-growth-capacity.svg?v=1"));background-size:cover;background-position:center}
.diagram-population-growth-capacity .part{display:none}

.diagram-species-interactions-niche{background-image:var(--thumbnail-load,url("/static/model-thumbnails/species-interactions-niche.svg?v=1"));background-size:cover;background-position:center}
.diagram-species-interactions-niche .part{display:none}

.diagram-community-succession-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/community-succession-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-community-succession-lab .part{display:none}

.diagram-food-web-builder-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/food-web-builder-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-food-web-builder-lab .part{display:none}

.diagram-energy-pyramids-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/energy-pyramids-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-energy-pyramids-lab .part{display:none}

.diagram-ecosystem-stability-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/ecosystem-stability-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-ecosystem-stability-lab .part{display:none}

.diagram-quadrat-survey-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/quadrat-survey-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-quadrat-survey-lab .part{display:none}

.diagram-mark-recapture-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/mark-recapture-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-mark-recapture-lab .part{display:none}

.diagram-population-structure-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/population-structure-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-population-structure-lab .part{display:none}

.diagram-yeast-growth-counting-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/yeast-growth-counting-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-yeast-growth-counting-lab .part{display:none}

.diagram-community-structure-richness-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/community-structure-richness-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-community-structure-richness-lab .part{display:none}

.diagram-biomes-adaptation-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/biomes-adaptation-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-biomes-adaptation-lab .part{display:none}

.diagram-carbon-pollutant-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/carbon-pollutant-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-carbon-pollutant-lab .part{display:none}

.diagram-soil-decomposition-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/soil-decomposition-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-soil-decomposition-lab .part{display:none}

.diagram-ecosystem-information-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/ecosystem-information-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-ecosystem-information-lab .part{display:none}

.diagram-human-impact-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/human-impact-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-human-impact-lab .part{display:none}

.diagram-biodiversity-conservation-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/biodiversity-conservation-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-biodiversity-conservation-lab .part{display:none}

.diagram-ecological-engineering-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/ecological-engineering-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-ecological-engineering-lab .part{display:none}

.diagram-maxwell-equations-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/maxwell-equations-lab.svg"));background-size:cover;background-position:center}




.diagram-pinhole-imaging-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/pinhole-imaging-3d.png"));background-size:cover;background-position:center}
.diagram-pinhole-imaging-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/pinhole-imaging-3d-png-c3305d03b130.webp"))}







.diagram-convex-lens-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/convex-lens-3d.png"));background-size:cover;background-position:center}
.diagram-convex-lens-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/convex-lens-3d-png-11bb627f9caa.webp"))}

.diagram-set-classification-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/set-classification-lab.svg"));background-size:cover;background-position:center}

.diagram-set-relations-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/set-relations-lab.svg"));background-size:cover;background-position:center}

.diagram-numberline-sets-lab{background-image:var(--thumbnail-load,url('/static/model-thumbnails/numberline-sets.svg'));background-size:cover;background-position:center}

.diagram-implication-conditions-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/implication-conditions-lab.svg"));background-size:cover;background-position:center}

.diagram-quantifiers-counterexamples-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/quantifiers-counterexamples-lab.svg"));background-size:cover;background-position:center}

.diagram-quadratic-three-links-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/quadratic-three-links-lab.svg"));background-size:cover;background-position:center}
.diagram-quadratic-three-links-lab .part{display:none}

.diagram-amgm-area-proof-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/amgm-area-proof-lab.svg"));background-size:cover;background-position:center}
.diagram-amgm-area-proof-lab .part{display:none}

.diagram-sum-product-extrema-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/sum-product-extrema-lab.svg"));background-size:cover;background-position:center}
.diagram-sum-product-extrema-lab .part{display:none}

.diagram-inequality-transform-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/inequality-transform-lab.svg"));background-size:cover;background-position:center}
.diagram-inequality-transform-lab .part{display:none}

.diagram-fence-optimization-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/fence-optimization-lab.svg"));background-size:cover;background-position:center}
.diagram-fence-optimization-lab .part{display:none}

.diagram-function-correspondence-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/function-correspondence-lab.svg"));background-size:contain;background-repeat:no-repeat;background-color:white;background-position:center}
.diagram-function-correspondence-lab .part{display:none}

.diagram-function-domain-range-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/function-domain-range-lab.svg"));background-size:contain;background-repeat:no-repeat;background-color:white;background-position:center}
.diagram-function-domain-range-lab .part{display:none}

.diagram-function-monotonicity-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/function-monotonicity-lab.svg"));background-size:contain;background-repeat:no-repeat;background-color:white;background-position:center}
.diagram-function-monotonicity-lab .part{display:none}

.diagram-function-parity-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/function-parity-lab.svg"));background-size:contain;background-repeat:no-repeat;background-color:white;background-position:center}
.diagram-function-parity-lab .part{display:none}

.diagram-power-functions-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/power-functions-lab.svg"));background-size:contain;background-repeat:no-repeat;background-color:white;background-position:center}
.diagram-power-functions-lab .part{display:none}

.diagram-piecewise-modeling-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/piecewise-modeling-lab.svg"));background-size:contain;background-repeat:no-repeat;background-color:white;background-position:center}
.diagram-piecewise-modeling-lab .part{display:none}

.diagram-angle-radian-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/angle-radian-lab.svg"));background-size:cover;background-position:center}
.diagram-angle-radian-lab .part{display:none}

.diagram-unit-circle-trig-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/unit-circle-trig-lab.svg"));background-size:cover;background-position:center}
.diagram-unit-circle-trig-lab .part{display:none}

.diagram-trig-reduction-symmetry-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/trig-reduction-symmetry-lab.svg"));background-size:cover;background-position:center}
.diagram-trig-reduction-symmetry-lab .part{display:none}

.diagram-trig-graph-properties-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/trig-graph-properties-lab.svg"));background-size:cover;background-position:center}
.diagram-trig-graph-properties-lab .part{display:none}

.diagram-trig-angle-sum-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/trig-angle-sum-lab.svg"));background-size:cover;background-position:center}
.diagram-trig-angle-sum-lab .part{display:none}

.diagram-trig-identities-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/trig-identities-lab.svg"));background-size:cover;background-position:center}
.diagram-trig-identities-lab .part{display:none}

.diagram-sine-parameters-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/sine-parameters-lab.svg"));background-size:cover;background-position:center}
.diagram-sine-parameters-lab .part{display:none}

.diagram-trig-periodic-modeling-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/trig-periodic-modeling-lab.svg"));background-size:cover;background-position:center}
.diagram-trig-periodic-modeling-lab .part{display:none}

.diagram-vector-composition-lab{background:#f3f7f0;background-image:var(--thumbnail-load,url("/static/model-thumbnails/vector-composition-lab.svg"));background-size:cover;background-position:center}
.diagram-vector-composition-lab .part{display:none}

.diagram-vector-properties-lab{background:#f3f7f0;background-image:var(--thumbnail-load,url("/static/model-thumbnails/vector-properties-lab.svg"));background-size:cover;background-position:center}
.diagram-vector-properties-lab .part{display:none}

.diagram-vector-subtraction-lab{background:#f3f7f0;background-image:var(--thumbnail-load,url("/static/model-thumbnails/vector-subtraction-lab.svg"));background-size:cover;background-position:center}
.diagram-vector-subtraction-lab .part{display:none}

.diagram-vector-scaling-lab{background:#f3f7f0;background-image:var(--thumbnail-load,url("/static/model-thumbnails/vector-scaling-lab.svg"));background-size:cover;background-position:center}
.diagram-vector-scaling-lab .part{display:none}

.diagram-vector-basis-lab{background:#f3f7f0;background-image:var(--thumbnail-load,url("/static/model-thumbnails/vector-basis-lab.svg"));background-size:cover;background-position:center}
.diagram-vector-basis-lab .part{display:none}

.diagram-vector-dot-product-lab{background:#f3f7f0;background-image:var(--thumbnail-load,url("/static/model-thumbnails/vector-dot-product-lab.svg"));background-size:cover;background-position:center}
.diagram-vector-dot-product-lab .part{display:none}

.diagram-triangle-solving-lab{background:#f3f7f0;background-image:var(--thumbnail-load,url("/static/model-thumbnails/triangle-solving-lab.svg"));background-size:cover;background-position:center}
.diagram-triangle-solving-lab .part{display:none}

.diagram-vector-applications-lab{background:#f3f7f0;background-image:var(--thumbnail-load,url("/static/model-thumbnails/vector-applications-lab.svg"));background-size:cover;background-position:center}
.diagram-vector-applications-lab .part{display:none}

.diagram-plane-mirror-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/plane-mirror-3d.png"));background-size:cover;background-position:center;}

.diagram-starch-statolith-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/starch-statolith-lab.svg?v=1"));background-size:cover;background-position:center}
.diagram-starch-statolith-lab .part{display:none}

.diagram-junior-genetics{background:#314238;background-image:var(--thumbnail-load,url("/static/model-thumbnails/junior-genetics-v2.png"));background-size:contain;background-position:center;background-repeat:no-repeat}
.diagram-junior-genetics .part{display:none}
.diagram-junior-genetics{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/junior-genetics-v2-png-d96a3e8aabe4.webp"))}













.diagram-neural-reflex{background:#26332f;background-image:var(--thumbnail-load,url("/static/model-thumbnails/neural-reflex-v2.png"));background-size:contain;background-position:center;background-repeat:no-repeat}
.diagram-neural-reflex .part{display:none}
.diagram-neural-reflex{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/neural-reflex-v2-png-eb59f14954d5.webp"))}

.diagram-exponent-expansion-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/exponent-expansion-lab.svg"));background-size:cover;background-position:center}

.diagram-exponential-functions-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/exponential-functions-lab.svg"));background-size:cover;background-position:center}

.diagram-logarithm-meaning-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/logarithm-meaning-lab.svg"));background-size:cover;background-position:center}

.diagram-exponential-logarithm-inverse-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/exponential-logarithm-inverse-lab.svg"));background-size:cover;background-position:center}

.diagram-growth-comparison-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/growth-comparison-lab.svg"));background-size:cover;background-position:center}

.diagram-zeros-bisection-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/zeros-bisection-lab.svg"));background-size:cover;background-position:center}

.diagram-exponential-modeling-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/exponential-modeling-lab.svg"));background-size:cover;background-position:center}

.diagram-optogenetics-immersive{background-image:var(--thumbnail-load,url("/static/model-thumbnails/optogenetics-immersive.webp"));background-size:cover;background-position:center;background-color:#07121d}
.diagram-optogenetics-immersive .part{display:none}
.diagram-optogenetics-immersive{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/optogenetics-immersive-webp-d74080ed3e8c.webp"))}

.diagram-flower-fruit{background:#214a3b;background-image:var(--thumbnail-load,url("/static/model-thumbnails/flower-fruit-v2.png"));background-size:contain;background-position:center;background-repeat:no-repeat}
.diagram-flower-fruit .part{display:none}
.diagram-flower-fruit{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/flower-fruit-v2-png-b1c38186d587.webp"))}

.diagram-complex-roots-lab{background:#f5f4f0;background-image:var(--thumbnail-load,url("/static/model-thumbnails/complex-roots-lab.svg"));background-size:cover;background-position:center}
.diagram-complex-roots-lab .part{display:none}

.diagram-complex-plane-lab{background:#f5f4f0;background-image:var(--thumbnail-load,url("/static/model-thumbnails/complex-plane-lab.svg"));background-size:cover;background-position:center}
.diagram-complex-plane-lab .part{display:none}

.diagram-complex-modulus-lab{background:#f5f4f0;background-image:var(--thumbnail-load,url("/static/model-thumbnails/complex-modulus-lab.svg"));background-size:cover;background-position:center}
.diagram-complex-modulus-lab .part{display:none}

.diagram-complex-add-subtract-lab{background:#f5f4f0;background-image:var(--thumbnail-load,url("/static/model-thumbnails/complex-add-subtract-lab.svg"));background-size:cover;background-position:center}
.diagram-complex-add-subtract-lab .part{display:none}

.diagram-complex-arithmetic-lab{background:#f5f4f0;background-image:var(--thumbnail-load,url("/static/model-thumbnails/complex-arithmetic-lab.svg"));background-size:cover;background-position:center}
.diagram-complex-arithmetic-lab .part{display:none}

.diagram-complex-polar-lab{background:#f5f4f0;background-image:var(--thumbnail-load,url("/static/model-thumbnails/complex-polar-lab.svg"));background-size:cover;background-position:center}
.diagram-complex-polar-lab .part{display:none}

.diagram-complex-transform-lab{background:#f5f4f0;background-image:var(--thumbnail-load,url("/static/model-thumbnails/complex-transform-lab.svg"));background-size:cover;background-position:center}
.diagram-complex-transform-lab .part{display:none}

.diagram-eye-vision{background:#1e3e57;background-image:var(--thumbnail-load,url("/static/model-thumbnails/eye-vision-v2.png"));background-size:contain;background-position:center;background-repeat:no-repeat}
.diagram-eye-vision .part{display:none}
.diagram-eye-vision{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/eye-vision-v2-png-c1ad46f3ca8a.webp"))}





.diagram-gravity-center-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/gravity-center-3d-v2.png"));background-size:cover;background-position:center}
.diagram-gravity-center-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/gravity-center-3d-v2-png-2d7af98a47db.webp"))}

.diagram-hydrometer-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/hydrometer-3d.jpg"));background-size:cover;background-position:center}
.diagram-hydrometer-3d .part{display:none}
.diagram-hydrometer-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/hydrometer-3d-jpg-194107660de3.webp"))}

.diagram-momentum-applications-3d{background:#081b28;background-image:var(--thumbnail-load,url("/static/model-thumbnails/momentum-applications-3d.png"));background-size:cover;background-position:center}
.diagram-momentum-applications-3d .part{display:none}
.diagram-momentum-applications-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/momentum-applications-3d-png-eb7f2bf1d277.webp"))}

.diagram-mri-principles-lab { background-image: var(--thumbnail-load, url("/static/model-thumbnails/mri-principles-lab.png")); background-size: cover; background-position: center; }
.diagram-mri-principles-lab{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/mri-principles-lab-png-2b7e288e0530.webp"))}








.diagram-f22-explorer{background-image:var(--thumbnail-load,url("/static/model-thumbnails/f22-explorer.png"));background-size:cover;background-position:center;}
.diagram-f22-explorer .part{display:none;}
.diagram-f22-explorer{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/f22-explorer-png-82bf0a25ba81.webp"))}
.diagram-f22-explorer{background-image:var(--thumbnail-load,url("/static/model-thumbnails/f22-explorer.png"));background-size:cover;background-position:center;}
.diagram-f22-explorer .part{display:none;}
.diagram-f22-explorer{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/f22-explorer-png-82bf0a25ba81.webp"))}

.diagram-mechanical-energy-verify-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/mechanical-energy-verify-3d.png"));background-size:contain;background-position:center;background-repeat:no-repeat;background-color:#18232b}
.diagram-mechanical-energy-verify-3d .part{display:none}
.diagram-mechanical-energy-verify-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/mechanical-energy-verify-3d-png-0eebf7fe47c5.webp"))}

.diagram-power-startup-3d{background-image:var(--thumbnail-load,url("/static/model-thumbnails/cards/power-startup-3d-png-4528291faeee.webp"))}