:root{--blue:#145bff;--ink:#171c25;--muted:#646e7d;--line:#e1e5eb;--soft:#f5f7fa;--paper:#fff;font-family:Inter,"Segoe UI",Arial,sans-serif;color:var(--ink);font-synthesis:none}*{box-sizing:border-box}body{margin:0;background:white;font-size:16px}button,input,select{font:inherit}button,a,select,input{touch-action:manipulation}button{cursor:pointer}button:disabled{cursor:not-allowed;opacity:.45}a{color:var(--blue)}button:focus-visible,a:focus-visible,select:focus-visible,input:focus-visible{outline:3px solid #7299ff;outline-offset:3px}button{background:none;border:0;color:inherit}h1,h2,h3,p{margin:0}h1{font-weight:450;font-size:clamp(28px,3vw,43px);letter-spacing:-1.8px;line-height:1.15}h2{font-size:25px;font-weight:500;letter-spacing:-.65px}h3{font-weight:550;font-size:18px}p{line-height:1.65}small{font-size:12px} .header{height:88px;display:flex;align-items:center;padding:0 34px;gap:35px;border-bottom:1px solid var(--line);position:relative;background:#fff;z-index:20}.brand{display:flex;align-items:center;gap:11px;text-decoration:none;color:var(--ink);font-size:24px;font-weight:650;letter-spacing:-1px;white-space:nowrap}.brand img{object-fit:contain}.brand-light{font-weight:400}.brand small{display:block;font-size:9px;letter-spacing:2.3px;color:var(--muted);margin-top:3px;font-weight:500}.header nav{display:flex;align-self:stretch;gap:25px;margin:auto}.header nav a{display:flex;align-items:center;color:var(--muted);text-decoration:none;font-size:14px;border-bottom:2px solid transparent;white-space:nowrap}.header nav a.active{color:var(--blue);border-color:var(--blue)}.source-short{font-size:13px;white-space:nowrap}.source-short span{margin-left:12px}.workspace{display:grid;grid-template-columns:215px minmax(0,1fr) 295px;min-height:calc(100svh - 88px)}.sidebar{border-right:1px solid var(--line);padding:26px 18px;display:flex;flex-direction:column;gap:24px}.eyebrow{font-family:"SFMono-Regular",Consolas,monospace;font-size:11px;letter-spacing:1.7px;text-transform:uppercase;color:var(--muted);line-height:1.6}.species-group{margin-top:18px}.group-title{font-size:12px;color:var(--muted);margin:0 0 9px 11px}.species-button{display:block;text-align:left;width:100%;padding:9px 11px;font-size:13px;border-left:2px solid transparent;line-height:1.4}.species-button.active{border-color:var(--blue);color:var(--blue);background:#f0f5ff}.species-button:hover{background:var(--soft)}.sidebar-bottom{margin-top:auto;border-top:1px solid var(--line);padding-top:18px;font-size:12px;line-height:1.6;color:var(--muted)}.explore-center{min-width:0;display:flex;flex-direction:column}.scene-heading{padding:32px 30px 12px;display:flex;justify-content:space-between;gap:12px;align-items:flex-start}.scene-heading .eyebrow{margin-bottom:10px}.species-sub{margin-top:12px;display:flex;gap:12px;align-items:center;font-size:12px;color:var(--muted)}.dot{width:5px;height:5px;background:var(--blue);border-radius:100%;display:inline-block}.stage-select{border:1px solid var(--line);padding:9px 12px;background:white;max-width:160px;font-size:13px;border-radius:4px}.viewer{position:relative;min-height:420px;flex:1;overflow:hidden;background:radial-gradient(ellipse at 50% 65%,#edf1f4 0,#f8fafb 44%,#fff 76%);isolation:isolate}.viewer canvas{display:block;width:100%;height:100%;position:absolute;inset:0;outline:none}.viewer-badge{position:absolute;top:18px;left:30px;font-size:11px;letter-spacing:.5px;color:#75808c;pointer-events:none}.viewer-hint{position:absolute;bottom:18px;left:30px;font-size:12px;color:var(--muted);pointer-events:none}.view-axis{position:absolute;bottom:18px;right:25px;display:flex;gap:5px}.view-axis button{background:#ffffffdf;border:1px solid var(--line);font-size:11px;padding:7px 8px;border-radius:3px}.hotspot{position:absolute;padding:5px 9px 5px 5px;background:#ffffffdf;border:1px solid #dde3ec;border-radius:20px;box-shadow:0 2px 10px #122b4310;font-size:11px;display:flex;align-items:center;gap:6px;white-space:nowrap;transform:translate(-5px,-50%);z-index:2}.hotspot:before{content:"";width:7px;height:7px;background:var(--blue);border:3px solid white;box-shadow:0 0 0 1px var(--blue);border-radius:50%}.hotspot.active{color:var(--blue);border-color:#7299ff}.viewer-error{position:absolute;inset:0;padding:65px 25px;text-align:center;display:grid;place-content:center;gap:15px;background:white}.toolbar{border-top:1px solid var(--line);display:flex;align-items:center;gap:7px;padding:15px 24px;flex-wrap:wrap;min-height:64px}.tool{font-size:12px;padding:9px 11px;border-radius:4px;display:inline-flex;gap:7px;align-items:center}.tool:hover,.tool.active{background:#eef3ff;color:var(--blue)}.tool svg{width:16px;height:16px}.tool-end{margin-left:auto}.detail{border-left:1px solid var(--line);padding:30px 25px;display:flex;flex-direction:column;gap:22px}.detail h2{font-size:30px}.detail .part-label{margin-bottom:6px}.tabline{display:flex;border-bottom:1px solid var(--line);gap:17px}.tabline button{font-size:13px;padding:0 0 12px;color:var(--muted);border-bottom:2px solid transparent}.tabline button.active{color:var(--blue);border-color:var(--blue)}.part-list{display:flex;flex-wrap:wrap;gap:6px}.part-list button{font-size:12px;padding:7px 10px;border:1px solid var(--line);border-radius:3px}.part-list button.active{border-color:var(--blue);color:var(--blue);background:#f6f8ff}.detail-copy{font-size:14px;line-height:1.75;color:#4d5868}.detail-copy strong{color:var(--ink);font-weight:550}.detail-facts{display:grid;gap:14px}.fact{padding-top:14px;border-top:1px solid var(--line)}.fact dt{font-size:11px;letter-spacing:1px;color:var(--muted);text-transform:uppercase;margin-bottom:7px}.fact dd{margin:0;font-size:13px;line-height:1.6}.source-note{font-size:11px;color:#707988;line-height:1.6}.source-note a{font-size:12px}.detail-bottom{margin-top:auto}.text-link{color:var(--blue);font-size:13px;display:inline-flex;gap:16px;padding:8px 0}.notice{background:#f4f6fa;border-left:2px solid #9baac0;font-size:12px;color:#536172;padding:11px 13px;line-height:1.6}.source-img{width:100%;max-height:230px;object-fit:contain;background:white;border:1px solid var(--line);padding:8px}.image-expand{padding:0;width:100%;cursor:zoom-in}.image-viewer{position:absolute;inset:0;background:white;z-index:4;display:flex;align-items:center;justify-content:center;flex-direction:column;padding:30px;gap:15px}.image-viewer img{max-height:75%;max-width:95%;object-fit:contain}.image-viewer p{font-size:12px;color:var(--muted)}.page{padding:38px 40px 55px;max-width:1600px;margin:auto}.page-head{display:flex;align-items:flex-end;justify-content:space-between;gap:25px;margin-bottom:30px}.page-head .eyebrow{margin-bottom:12px}.page-intro{color:var(--muted);font-size:14px;max-width:600px;margin-top:15px}.compare-control{display:flex;gap:18px;flex-wrap:wrap;align-items:center}.compare-grid{display:grid;grid-template-columns:1fr 1fr;border:1px solid var(--line);border-radius:5px;overflow:hidden}.compare-pane{min-width:0}.compare-pane+ .compare-pane{border-left:1px solid var(--line)}.compare-top{padding:20px 24px;display:flex;align-items:center;justify-content:space-between;gap:12px}.compare-top select{border:0;border-bottom:1px solid var(--line);padding:8px 24px 8px 0;background:white;font-size:20px;max-width:100%;font-weight:500}.compare-top small{color:var(--muted);white-space:nowrap}.compare-pane .viewer{height:420px;min-height:340px}.compare-table{width:100%;border-collapse:collapse;font-size:14px;margin-top:25px}.compare-table th{text-align:left;background:var(--soft);font-weight:500;padding:15px 20px}.compare-table td{padding:17px 20px;border-bottom:1px solid var(--line);vertical-align:top;line-height:1.6;width:38%}.compare-table td:first-child{width:24%;color:var(--muted)}.compare-table .difference td:not(:first-child){color:#174dc3}.check{display:flex;align-items:center;gap:9px;font-size:13px}.check input{accent-color:var(--blue);width:17px;height:17px}.section-strip{border-top:1px solid var(--line);padding-top:20px;display:flex;align-items:center;justify-content:space-between;gap:20px;margin-top:25px}.primary{padding:12px 18px;background:var(--blue);color:white;border-radius:4px;font-size:14px;border:1px solid var(--blue)}.secondary{padding:12px 18px;border:1px solid var(--line);border-radius:4px;font-size:14px;background:white}.primary:hover{background:#064ce6}.procedure-grid{display:grid;grid-template-columns:minmax(0,1fr) 315px;border:1px solid var(--line)}.procedure-grid .viewer{height:530px}.procedure-aside{padding:28px;border-left:1px solid var(--line)}.procedure-aside h2{margin:10px 0 15px}.procedure-aside p{font-size:14px;color:#586474}.chapters{margin:26px 0 0;padding:0;list-style:none}.chapters button{display:flex;text-align:left;gap:15px;width:100%;padding:16px 0;font-size:13px;border-bottom:1px solid var(--line);line-height:1.4}.chapters button.active{color:var(--blue)}.chapters .number{font-family:Consolas,monospace;color:#8590a0}.player{padding:18px 24px;border-top:1px solid var(--line);display:flex;gap:18px;align-items:center}.player input[type=range]{flex:1;min-width:50px;accent-color:var(--blue)}.player button{font-size:14px}.player select{border:1px solid var(--line);padding:6px;background:white;font-size:12px}.timer{font:12px Consolas,monospace;color:var(--muted)}.subtitle{padding:12px 24px;background:#f3f6fc;border-top:1px solid var(--line);font-size:13px;line-height:1.6;min-height:64px}.layer-control{margin-top:22px;font-size:12px;color:var(--muted)}.layer-control label{display:flex;justify-content:space-between;margin-bottom:10px}.layer-control input{width:100%;accent-color:var(--blue)}.module-layout{display:grid;grid-template-columns:230px minmax(0,1fr);gap:45px}.module-menu button{display:block;width:100%;text-align:left;padding:15px 12px;border-bottom:1px solid var(--line);font-size:14px}.module-menu button.active{color:var(--blue);border-left:2px solid var(--blue);background:#f5f8ff}.lesson{max-width:880px}.lesson h2{font-size:32px;margin-bottom:20px}.lesson p{font-size:15px;color:#536070;margin-bottom:20px}.lesson h3{margin-top:28px;margin-bottom:12px}.lesson ol,.lesson ul{padding-left:22px;line-height:1.8;font-size:15px;color:#536070}.lesson li{margin-bottom:9px}.lesson .notice{margin-top:25px}.lesson .source-note{margin-top:18px}.lesson-grid{display:grid;grid-template-columns:1fr 1fr;gap:25px}.lesson-block{padding:23px 0;border-top:1px solid var(--line)}.lesson-block h3{margin-top:0}.lesson-block p{margin-bottom:0}.metric-form{display:grid;grid-template-columns:1fr 1fr;gap:18px;padding:22px;background:#f6f8fb;margin:20px 0}.metric-form label{font-size:13px;display:grid;gap:9px}.metric-form input{width:100%;padding:10px;border:1px solid var(--line);background:white;border-radius:3px}.metric-result{grid-column:1/-1;font-size:20px;color:var(--blue);min-height:28px}.identify-layout{display:grid;grid-template-columns:minmax(0,1fr) 340px;gap:50px;max-width:1100px;margin:auto}.identify-card{padding:30px;border:1px solid var(--line)}.identify-card h2{line-height:1.4;margin:14px 0 24px}.answer{display:block;text-align:left;width:100%;padding:17px 19px;border:1px solid var(--line);margin-top:12px;border-radius:4px;font-size:15px;line-height:1.5}.answer:hover{color:var(--blue);border-color:var(--blue);background:#f7f9ff}.answer span{float:right}.identify-art img{width:100%;max-height:360px;object-fit:contain}.identify-art p{font-size:12px;color:var(--muted);margin-top:15px}.sources-list{display:grid;gap:0}.source-row{padding:20px 0;border-top:1px solid var(--line);display:grid;grid-template-columns:48px 1fr 160px;gap:20px}.source-row h3{font-size:15px;font-weight:500;line-height:1.5}.source-row p{font-size:12px;color:var(--muted);margin-top:6px}.source-row .index{color:#8893a4;font:13px Consolas,monospace}.source-status{text-align:right;font-size:11px;color:var(--muted)}.source-links{display:flex;gap:22px;flex-wrap:wrap;margin-top:22px;font-size:13px}.modal{border:1px solid var(--line);max-width:min(1000px,95vw);max-height:92svh;padding:22px;border-radius:6px}.modal::backdrop{background:#0c1427b0;backdrop-filter:blur(4px)}.modal img{display:block;max-width:100%;max-height:73svh;object-fit:contain;margin:20px auto}.modal .close{float:right;padding:5px 12px;border:1px solid var(--line)}.modal p{font-size:12px;color:var(--muted)}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}.skip{position:fixed;top:-100px;left:10px;z-index:100;background:white;padding:12px}.skip:focus{top:10px}.mobile-species{display:none}.loading{display:grid;place-items:center;min-height:400px;color:var(--muted)}@media(min-width:1550px){.workspace{grid-template-columns:240px minmax(0,1fr) 330px}.viewer{min-height:550px}}@media(max-width:1150px){.header{padding:0 22px;gap:20px}.header nav{gap:16px}.workspace{grid-template-columns:180px minmax(0,1fr) 255px}.detail{padding:25px 19px}.scene-heading{padding:28px 20px 10px}.sidebar{padding:24px 10px}.source-short{display:none}.viewer{min-height:420px}.species-button{font-size:12px}.procedure-grid{grid-template-columns:minmax(0,1fr) 275px}.page{padding:32px 24px}}@media(max-width:850px){.header{height:auto;min-height:78px;flex-wrap:wrap;padding:16px 20px 0;gap:12px}.brand{font-size:22px}.brand small{display:none}.header nav{order:2;width:100%;overflow:auto;gap:24px;min-height:43px;justify-content:flex-start}.header nav a{font-size:13px;padding-bottom:10px}.workspace{grid-template-columns:minmax(0,1fr) 260px;min-height:0}.sidebar{display:none}.mobile-species{display:block;border:1px solid var(--line);padding:8px;background:white;font-size:13px;max-width:220px}.scene-heading{display:block}.scene-heading h1{margin-top:14px}.scene-heading .stage-select{margin-top:12px}.detail{padding-top:28px}.viewer{min-height:440px}.scene-heading .eyebrow{display:none}.page-head{align-items:flex-start;flex-direction:column}.procedure-grid{grid-template-columns:1fr}.procedure-aside{border-left:0;border-top:1px solid var(--line);display:block}.procedure-grid .viewer{height:440px}.chapters{display:flex;gap:10px;overflow:auto}.chapters li{min-width:140px}.chapters button{border:0}.module-layout{grid-template-columns:1fr;gap:28px}.module-menu{display:flex;overflow:auto;gap:12px}.module-menu button{width:auto;white-space:nowrap;border:1px solid var(--line);border-radius:3px}.module-menu button.active{border:1px solid var(--blue)}.identify-layout{grid-template-columns:1fr 270px;gap:25px}.compare-top{padding:15px}.compare-top select{font-size:17px}.compare-top small{display:none}.compare-pane .viewer{height:340px;min-height:300px}.source-row{grid-template-columns:30px 1fr}.source-status{grid-column:2;text-align:left}.source-row{gap:10px}}@media(max-width:600px){h1{font-size:31px}.workspace{display:block}.detail{border-left:0;border-top:1px solid var(--line);gap:18px;padding:24px}.scene-heading{padding:23px 21px 0;position:relative}.scene-heading .stage-select{position:absolute;top:14px;right:20px;max-width:100px}.mobile-species{max-width:205px}.viewer{min-height:400px;height:400px}.viewer-badge{left:20px;font-size:10px}.viewer-hint{left:20px;font-size:10px;bottom:15px}.view-axis{right:15px;bottom:35px}.hotspot{font-size:10px;padding:4px 7px 4px 4px}.toolbar{padding:12px;gap:0}.tool{font-size:11px;padding:9px 8px}.detail h2{font-size:27px}.detail-facts{grid-template-columns:1fr 1fr;gap:20px}.page{padding:28px 20px}.page-head{margin-bottom:24px}.compare-grid{grid-template-columns:1fr}.compare-pane+.compare-pane{border-left:0;border-top:1px solid var(--line)}.compare-pane .viewer{height:300px;min-height:300px}.compare-table{font-size:12px}.compare-table td,.compare-table th{padding:12px 9px;overflow-wrap:anywhere}.compare-control{gap:12px}.procedure-grid .viewer{height:400px;min-height:400px}.player{padding:15px 12px;gap:9px;flex-wrap:wrap}.player input[type=range]{min-width:100px}.timer{font-size:11px}.procedure-aside{padding:23px}.subtitle{padding:15px;font-size:12px}.identify-layout{display:flex;flex-direction:column}.identify-art{order:-1}.identify-art img{max-height:180px}.identify-art p{font-size:11px}.identify-card{padding:22px}.lesson-grid{grid-template-columns:1fr;gap:0}.lesson h2{font-size:27px}.metric-form{grid-template-columns:1fr}.section-strip{align-items:flex-start;flex-direction:column}.source-row h3{font-size:13px}.header nav{gap:21px}.header{padding-left:20px;padding-right:20px}.source-img{max-height:260px}.detail-bottom{margin-top:0}}@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important;animation:none!important}}

@media(min-width:851px){.workspace{height:calc(100svh - 88px);min-height:620px}.sidebar,.detail{overflow-y:auto}.explore-center>.viewer{min-height:290px}.detail{gap:18px}.source-img{max-height:185px}}

[hidden]{display:none!important}
.player #play{min-width:132px;white-space:nowrap}.playback-hint{font-size:11px;color:var(--muted)}@media(max-width:600px){.playback-hint{flex-basis:100%;order:5}}
body{display:flex;flex-direction:column;min-height:100svh}.header{flex-shrink:0}#main{flex:1;min-width:0}.site-footer{width:calc(100% - 80px);max-width:1520px;margin:0 auto;border-top:1px solid var(--line);padding:20px 0;font-size:12px;line-height:20px;color:var(--muted)}.site-footer a{text-underline-offset:3px}html{scroll-behavior:smooth}.page,.workspace{animation:page-enter .26s cubic-bezier(.2,.7,.3,1) both}button,a,input,select,textarea{transition:color .16s ease,background-color .16s ease,border-color .16s ease,box-shadow .16s ease}.about-submit:hover{box-shadow:0 4px 12px #145bff20}.species-button,.module-menu button,.material-menu button{transition:color .16s ease,background-color .16s ease,border-color .16s ease}@keyframes page-enter{from{opacity:0;transform:translateY(6px)}to{opacity:1;transform:translateY(0)}}@media(min-width:851px){.workspace{height:calc(100svh - 149px)}}@media(max-width:600px){.site-footer{width:calc(100% - 40px)}}
.surveillance-page .page-head>div{width:100%}.surveillance-page .page-intro,.surveillance-page .lesson{max-width:none}
.about-facilitators{padding-left:24px;margin:14px 0 18px;color:#536070;font-size:15px;line-height:1.8}.about-facilitators li+li{margin-top:4px}.about-copy a{text-decoration:none}.about-copy a:hover{text-decoration:underline}.about-copy a strong{color:var(--blue)}
.about-page{max-width:1100px;padding-top:48px}.about-page h1{font-size:32px;letter-spacing:-1px}.about-story{display:grid;grid-template-columns:240px minmax(0,1fr);gap:44px;align-items:center;padding-bottom:32px}.about-logo{width:100%;height:auto;object-fit:contain}.about-copy{border-left:1px solid var(--line);padding-left:36px}.about-copy p,.about-contact>p{font-size:15px;color:#536070}.about-copy p+p{margin-top:18px}.about-copy strong{color:var(--ink);font-weight:600}.about-contact{border-top:1px solid var(--line);padding-top:30px}.about-contact h2{margin-bottom:12px}.about-email{display:inline-flex;align-items:center;gap:10px;margin-top:15px;text-decoration:none;font-size:14px;overflow-wrap:anywhere}.about-email svg{width:20px;height:20px;flex-shrink:0}.about-form{display:grid;gap:18px;margin-top:28px}.about-fields{display:grid;grid-template-columns:1fr 1fr;gap:24px}.about-form label{display:grid;gap:9px;font-size:13px}.about-form input,.about-form textarea{width:100%;padding:12px 14px;border:1px solid var(--line);border-radius:4px;background:white;color:var(--ink);font:inherit;font-size:14px}.about-form textarea{resize:vertical;min-height:130px;line-height:1.6}.about-form textarea:focus-visible{outline:3px solid #7299ff;outline-offset:3px}.about-form input::placeholder,.about-form textarea::placeholder{color:#8490a1}.about-submit{justify-self:start;display:inline-flex;align-items:center;gap:24px;background:var(--blue);color:white;padding:13px 22px;border-radius:4px;font-size:14px;min-height:44px}.about-submit:hover{background:#094add}.about-submit span{font-size:20px}.about-footer{margin-top:32px;padding-top:18px;border-top:1px solid var(--line)}@media(min-width:851px) and (max-width:1280px){.header{gap:20px}.header nav{gap:17px}.header nav a{font-size:13px}}@media(max-width:650px){.about-page{padding-top:30px}.about-page h1{font-size:28px}.about-story{grid-template-columns:1fr;gap:22px}.about-logo{width:180px;justify-self:center}.about-copy{border-left:0;padding-left:0}.about-fields{grid-template-columns:1fr;gap:18px}.about-email{font-size:13px}}

@media(max-width:600px){.toolbar .tool{padding:10px 6px;font-size:11px;gap:4px;min-height:40px}.toolbar .tool-end{margin-left:0}.toolbar{justify-content:space-between}}




.viewer canvas{touch-action:none}.viewer-badge,.viewer-hint{z-index:3}.view-axis{z-index:4}.hotspot{z-index:5}.image-viewer{z-index:8}.separation-control{position:absolute;top:44px;right:20px;z-index:6;display:grid;grid-template-columns:1fr 36px;gap:8px 10px;padding:12px;background:#ffffffee;border:1px solid #dfe5ed;border-radius:6px;font-size:12px;width:205px}.separation-control span{grid-column:1/-1}.separation-control input{width:100%;accent-color:#145bff}.separation-control output{font-variant-numeric:tabular-nums;text-align:right}.separation-control:focus-within{border-color:#145bff}
#procedure-view .hotspot{display:none}
.procedure-art{height:530px;position:relative;display:grid;place-items:center;background:linear-gradient(135deg,#f3f7ff,#e8eef8);overflow:hidden}.procedure-art-badge{position:absolute;z-index:2;top:18px;left:22px;padding:7px 10px;background:#ffffffdd;border:1px solid #dbe4f2;border-radius:3px;font:11px Consolas,monospace;letter-spacing:1px;color:#526174}.storyboard-frame{position:relative;height:min(86%,470px);max-width:86%;aspect-ratio:1;overflow:hidden;background:white;border-radius:12px;box-shadow:0 18px 50px #15315b24}.storyboard-frame img{position:absolute;inset:0;width:300%;height:200%;max-width:none;transition:transform .35s ease;object-fit:fill}.procedure-dots{position:absolute;bottom:18px;display:flex;gap:7px}.procedure-dots span{width:7px;height:7px;border-radius:50%;background:#aeb9c9}.procedure-dots span.active{width:22px;border-radius:10px;background:var(--blue)}
@media(max-width:850px){.procedure-art{height:440px}}
@media(max-width:600px){.procedure-art{height:400px}.storyboard-frame{height:auto;width:88%;max-width:none}.procedure-art-badge{top:12px;left:12px}}
@media(prefers-reduced-motion:reduce){.storyboard-frame img{transition:none}}

.material-layout{display:grid;grid-template-columns:220px minmax(0,1fr);gap:44px}.material-menu{position:sticky;top:25px;align-self:start}.material-menu button{display:block;width:100%;padding:14px 12px;text-align:left;border-bottom:1px solid var(--line);font-size:14px}.material-menu button.active{color:var(--blue);border-left:2px solid var(--blue);background:#f5f8ff}.material-article{max-width:980px}.material-hero{display:grid;grid-template-columns:minmax(300px,1.15fr) 1fr;align-items:center;gap:34px;border-bottom:1px solid var(--line);padding-bottom:30px}.material-hero img{width:100%;aspect-ratio:4/3;object-fit:cover;border-radius:8px;background:var(--soft)}.material-hero h2{font-size:clamp(27px,3vw,38px);line-height:1.2;margin:10px 0 16px}.material-hero p,.material-sections p{color:#536070;font-size:15px}.material-facts{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));margin:0;border-bottom:1px solid var(--line)}.material-facts div{padding:20px 0}.material-facts div+div{padding-left:28px;border-left:1px solid var(--line)}.material-facts dt{font:11px Consolas,monospace;letter-spacing:1px;text-transform:uppercase;color:var(--muted);margin-bottom:8px}.material-facts dd{margin:0;font-size:15px}.material-sections{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:28px}.material-sections section{padding:30px 0 20px}.material-sections h3,.material-remember h3{margin-bottom:12px}.material-remember{background:#f4f7fc;border-left:3px solid var(--blue);padding:20px 24px;margin:8px 0 20px}.material-remember ul{margin:0;padding-left:20px;line-height:1.7;color:#536070}.material-remember li+li{margin-top:7px}@media(max-width:850px){.material-layout{grid-template-columns:1fr;gap:28px}.material-menu{position:static;display:flex;overflow:auto;gap:8px}.material-menu button{width:auto;white-space:nowrap;border:1px solid var(--line);border-radius:3px}.material-menu button.active{border:1px solid var(--blue)}.material-hero{grid-template-columns:1fr 1fr}}@media(max-width:600px){.material-hero{grid-template-columns:1fr;gap:22px}.material-sections{grid-template-columns:1fr;gap:0}.material-sections section{border-bottom:1px solid var(--line)}.material-facts{grid-template-columns:1fr}.material-facts div+div{padding-left:0;border-left:0;border-top:1px solid var(--line)}}
.material-lifecycle{padding:34px 0 12px;border-bottom:1px solid var(--line)}.material-lifecycle>h3{font-size:27px;margin:8px 0 22px}.material-lifecycle .lifecycle-visuals{display:grid;grid-template-columns:1fr;gap:18px;margin-bottom:22px}.lifecycle-visuals figure{margin:0;border:1px solid var(--line);border-radius:10px;overflow:hidden;background:#fbfaf7}.lifecycle-visuals img{display:block;width:100%;height:auto;object-fit:contain}.lifecycle-visuals figcaption{padding:10px 13px;font-size:13px;font-weight:700;color:#263548}.material-lifecycle .lifecycle-steps{display:grid;grid-template-columns:1fr}.material-lifecycle article{padding:18px 0;border-top:1px solid var(--line)}.material-lifecycle h4{font-size:15px;margin:0 0 8px;color:#174dc3}.material-lifecycle p{font-size:14px;color:#536070}.material-sections{grid-template-columns:1fr;gap:0}.material-sections section{border-top:1px solid var(--line)}
.lesson-grid{grid-template-columns:1fr;gap:0}.lesson-block figure{margin:16px 0 18px;border:1px solid var(--line);border-radius:10px;overflow:hidden;background:#fbfaf7}.lesson-block figure img{display:block;width:100%;height:auto}.metric-form{grid-template-columns:1fr}.lesson-references{padding:6px 0 24px}.lesson-references ul{margin:0}.lesson-references li{margin-bottom:8px}.lesson-references a{font-size:13px}
.formula-list,.index-calculators{display:grid;gap:14px;margin-top:20px}.formula-card,.index-calculator{border:1px solid var(--line);border-radius:8px;padding:18px;background:#fff}.formula-card h4,.index-calculator h4{margin:0 0 12px;font-size:16px}.formula-equation{display:flex;align-items:center;gap:14px}.fraction{display:grid;text-align:center;max-width:360px;width:100%;font-size:13px}.fraction span{padding:7px}.fraction span:first-child{border-bottom:1px solid var(--ink)}.formula-equation strong{white-space:nowrap;color:var(--blue)}.index-calculator>p{font-size:13px;margin:0;color:var(--muted)}.index-calculator .metric-form{padding:16px;margin:14px 0 0}.index-calculator .metric-result{font-size:18px}
.back-to-top{position:fixed;right:24px;bottom:24px;z-index:30;width:48px;height:48px;border-radius:50%;background:var(--blue);color:#fff;box-shadow:0 8px 24px #0b3ca140;opacity:0;transform:translateY(12px);pointer-events:none;transition:opacity .2s,transform .2s;display:grid;place-items:center}.back-to-top svg{width:28px;height:28px}.back-to-top.visible{opacity:1;transform:none;pointer-events:auto}.back-to-top:hover{background:#064ce6}@media(max-width:600px){.back-to-top{right:16px;bottom:16px;width:44px;height:44px}}
/* The programmatically focused content region is not an interactive control. */
#main:focus{outline:none}