/* styles.css */
:root{color-scheme:dark;--bg:#080f1c;--panel:#101c2c;--line:#26384c;--muted:#9bacc0;--text:#edf5fc;--cyan:#62d1f3;font-family:'DM Sans',sans-serif;font-size:16px}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--text)}a{color:inherit;text-decoration:none}button,input{font:inherit}button,a,input{outline-offset:5px}button{cursor:pointer;color:inherit}button:disabled{cursor:default;opacity:.45}h1,h2,h3,p{margin:0}h1,h2,h3{font-family:'Space Grotesk',sans-serif}h1{font-size:clamp(32px,3.5vw,46px);line-height:1.15;letter-spacing:-1.5px}h2{font-size:25px;letter-spacing:-.7px}h3{font-size:19px}p{color:var(--muted);line-height:1.8}a:hover{color:#a4e9ff}.topbar{max-width:1260px;margin:auto;padding:25px 36px;display:flex;align-items:center;gap:55px;border-bottom:1px solid #203146}.brand{display:flex;gap:10px;align-items:center;font:700 26px 'Space Grotesk';letter-spacing:-1px}.brand svg{width:32px;height:36px}.cyan{color:var(--cyan)}nav{display:flex;gap:28px;font-size:14px;color:var(--muted)}nav a[aria-current]{color:white}.header-channel{margin-left:auto;color:#a9bed2;font-size:14px}.topbar a{padding:4px 0}main{max-width:1190px;margin:auto;padding:45px 36px 70px;min-height:75vh}.kicker{display:block;font-size:12px;font-weight:600;letter-spacing:1.7px;text-transform:uppercase;color:#7fc6e2;margin-bottom:12px}.course-intro{margin-bottom:30px}.course-intro p{margin-top:15px}.current-card{display:grid;grid-template-columns:1.1fr 1fr;background:#12243a;border:1px solid #35516b;border-radius:16px;overflow:hidden}.current-copy{padding:36px}.tag{display:inline-flex;padding:6px 9px;border:1px solid #355168;border-radius:5px;font-size:11px;letter-spacing:.7px;color:#b0d3e7;background:#11283b}.current-copy h2{font-size:32px;margin:21px 0 14px}.current-copy p{max-width:430px;margin-bottom:25px;color:#b9cbdd}.current-copy small{display:block;color:#8da8be;font-size:12px;margin-top:16px}.primary{display:inline-flex;justify-content:center;align-items:center;border:1px solid #61cce7;border-radius:8px;background:#269ecd;color:#fff;padding:13px 21px;font-size:15px;font-weight:600}.primary:hover:not(:disabled){background:#2aaedb;color:#fff}.current-art{background:linear-gradient(90deg,#12243a,transparent 38%),url('assets/hero.png') 72% center/cover;min-height:280px}.section-title{display:flex;align-items:end;justify-content:space-between;gap:24px;margin:42px 0 22px}.section-title .kicker{margin-bottom:8px}.subtle{font-size:13px;color:#8fa4b9;line-height:1.7}.level-list{display:grid;gap:12px}.level-row{display:flex;gap:22px;padding:24px;border:1px solid var(--line);border-radius:12px;background:#0e1929;align-items:flex-start}.level-number{display:grid;place-items:center;background:#182c41;border:1px solid #31516b;border-radius:50%;width:44px;height:44px;flex:none;color:#8ddbfa;font:500 17px 'Space Grotesk'}.level-info{flex:1}.level-info p{font-size:14px;margin-top:5px}.level-row.current{border-color:#3e6b89;background:#112136}.level-row.locked{background:#0b1523}.locked h3{color:#a1b0c1}.locked .level-number{background:#101d2d;color:#7f93aa;border-color:#253a51}.locked .tag{color:#8c9cac;border-color:#2b3c50;background:#111c2a}.lesson-links{display:flex;gap:9px;flex-wrap:wrap;margin-top:15px;font-size:13px}.lesson-links a,.locked-lesson{padding:7px 10px;border-radius:5px;border:1px solid #29465e;color:#a9d6eb}.lesson-links a:hover{border-color:#66b5d2;background:#173b54}.lesson-links .next-lesson{background:#1a3d57;color:#d3f1ff}.lesson-links .locked-lesson{color:#778b9e;border-color:transparent}.locked .lesson-links{color:#758b9f;font-size:12px;margin-top:8px}.success{color:#85d6b6;border-color:#2e6357;background:#132d28}.video-card{display:flex;gap:20px;align-items:flex-start;padding:28px;border:1px solid #2d3e54;background:#101b2b;border-radius:12px;margin-top:30px}.video-icon{font-size:32px;line-height:1;color:#f6938d;width:48px;height:48px;display:grid;place-items:center;border-radius:12px;background:#34252e;flex:none}.video-card>div{flex:1}.video-card .kicker{color:#c59ea3;font-size:11px;margin-bottom:8px}.video-card p{font-size:14px;margin-top:10px;max-width:590px}.channel-link{display:inline-flex;gap:14px;align-items:center;color:#93d9f0;font-size:14px;margin-top:17px}.lesson-top{display:flex;gap:25px;align-items:center;color:#8fa4b9;font-size:13px;margin:0 0 36px}.lesson-top span:last-child{margin-left:auto}.back-link{display:inline-block;color:#a7d9ef;font-size:14px}.lesson-layout{display:grid;grid-template-columns:minmax(0,730px) 285px;gap:40px;align-items:start}.lesson h1{font-size:37px;margin-bottom:24px}.lead{color:#c1d0df;font-size:18px;line-height:1.85}.example{border-left:2px solid #3a86a7;padding:3px 0 3px 22px;margin:28px 0}.example .kicker{margin-bottom:7px}.example p{color:#adbfd3}.equation{padding:23px;border:1px solid #2d4b64;background:#102237;border-radius:9px;font-family:'Space Grotesk';color:#9cdef6;font-size:23px;line-height:1.5;text-align:center;margin:28px 0}.lesson-aside{position:sticky;top:24px}.lesson-aside .video-card{margin:0;padding:23px;display:block}.lesson-aside .video-icon{margin-bottom:20px}.lesson-aside .tag{margin-top:20px}.lesson-aside h3{font-size:19px;line-height:1.5}.level-summary{padding:24px 8px}.level-summary h3{font-size:16px}.level-summary ol{padding-left:19px;display:grid;gap:16px;color:#7d90a7;font-size:14px;line-height:1.7}.level-summary .selected{color:#89ddf7}.level-summary a:hover{color:#c5f1ff}.activity{margin:30px 0 14px;border:1px solid #30485f;border-radius:12px;background:#0e1d2f;overflow:hidden;padding:22px}.activity header{display:flex;align-items:center;justify-content:space-between;gap:15px}.activity h3{font-size:19px}.activity .kicker{margin-bottom:7px}.quiet{padding:7px 11px;font-size:13px;border-radius:6px;color:#a4d8ed;border:1px solid #2c4b63;background:#112940}.quiet:hover{border-color:#78bfd6}.activity-diagram{display:block;width:100%;height:230px}.activity-diagram text{font-family:'DM Sans';font-size:13px;fill:#a3c2d7}.activity-controls{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:20px}.activity-controls label{font-size:14px;color:#b3cbdf}.activity-controls output{float:right;color:#e1f4ff}.activity-controls input{display:block;width:100%;accent-color:#6dd4f5;margin:18px 0 12px;cursor:pointer}.activity-result{border-top:1px solid #263e54;padding-top:17px;margin-top:10px}.activity-result strong{font:500 27px 'Space Grotesk';color:#9ee6fa}.activity-result p{font-size:13px;margin-top:6px}.model-note{font-size:12px;color:#7994ac;border-top:1px solid #22384e;padding-top:15px;margin-top:18px}.try-prompt{font-size:15px}.takeaway{border-left:3px solid #60b7b8;background:#10252e;border-radius:0 8px 8px 0;padding:21px 24px;margin:32px 0}.takeaway .kicker{color:#95d1ca;margin-bottom:8px}.takeaway p{color:#c0d6d8}.knowledge-check{padding:26px;border:1px solid #2c4058;border-radius:12px;margin-top:32px;background:#101b2b}.knowledge-check h2{font-size:21px;line-height:1.6;margin-bottom:20px}.answers{display:grid;gap:10px}.answers button{display:flex;align-items:center;gap:14px;text-align:left;padding:15px;border:1px solid #30445a;background:#0d1726;border-radius:8px;font-size:15px}.answers button span{display:grid;place-items:center;border:1px solid #3c5670;border-radius:50%;width:26px;height:26px;flex:none;font-size:12px;color:#9ebacf}.answers button:hover:not(:disabled){border-color:#72b3d1}.answers button.correct{background:#123b32;border-color:#559f88;opacity:1}.answers button.incorrect{border-color:#c57d74}.feedback{margin-top:18px;font-size:14px;color:#a2c6d8;min-height:25px}.lesson-finish{display:flex;align-items:center;gap:20px;margin-top:28px}.lesson-finish small{font-size:13px;color:#8ba4ba}.anatomy-actions{display:flex;flex-wrap:wrap;gap:8px}#part-explanation{font-size:14px;margin-top:17px}.completion,.locked-screen{max-width:700px;margin:30px auto;text-align:center}.completion-check{display:grid;place-items:center;margin:0 auto 28px;width:72px;height:72px;background:#183d36;color:#8adbbd;border-radius:50%;font-size:34px}.completion p,.locked-screen p{font-size:17px;margin:24px 0;line-height:1.9}.completion .back-link{margin-top:30px}.next-card{margin-top:35px;padding:30px;background:#112239;border:1px solid #35536c;border-radius:12px}.next-card p{font-size:14px;margin:10px 0 22px}.locked-screen .tag{margin-bottom:25px}.locked-screen .back-link{display:block;margin-top:25px}.progress-track{height:9px;border-radius:10px;background:#1d3045;overflow:hidden;margin:35px 0}.progress-track div{height:100%;background:#55bee7}.progress-levels{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin-bottom:32px}.progress-levels section{padding:23px;display:flex;gap:20px;border:1px solid #273c53;border-radius:10px;background:#0f1d2e}.progress-levels h3{font-size:18px}.progress-levels p{font-size:14px;margin-top:7px}.notice{border-left:3px solid #e8b06c;padding:14px 18px;background:#30261d;color:#e6c097;margin-bottom:20px;font-size:14px}footer{max-width:1190px;margin:auto;border-top:1px solid #1e2e42;padding:24px 36px 35px;font-size:12px;color:#6f879f;display:flex;justify-content:space-between;gap:20px}@media(max-width:1000px){.lesson-layout{grid-template-columns:minmax(0,1fr) 250px;gap:24px}.topbar{gap:30px}.current-copy{padding:28px}.current-art{background-position:65% center}.video-card>.tag{display:none}}@media(max-width:760px){main{padding:30px 20px 45px}.topbar{padding:20px;gap:20px;flex-wrap:wrap}.brand{font-size:24px}.header-channel{display:none}nav{margin-left:auto;gap:18px;font-size:13px}.current-card{grid-template-columns:1fr}.current-art{display:none}.current-copy{background:linear-gradient(90deg,#12243af5,#12243acc),url('assets/hero.png') center/cover;padding:28px}.current-copy h2{font-size:29px}.level-row{gap:13px;padding:20px 16px}.level-row>.tag{font-size:10px;padding:5px;max-width:76px}.level-number{width:34px;height:34px;font-size:14px}.level-info h3{font-size:17px}.level-info p{font-size:13px}.lesson-links{gap:7px}.lesson-links a,.locked-lesson{font-size:12px}.section-title{align-items:start}.section-title h2{font-size:23px}.section-title>.subtle{white-space:nowrap;font-size:12px}.video-card{padding:22px;gap:15px}.lesson-layout{display:flex;flex-direction:column}.lesson{width:100%}.lesson-aside{position:static;width:100%;display:flex;gap:20px}.lesson-aside>.video-card{flex:1}.level-summary{display:none}.lesson-top{gap:13px;font-size:12px;margin-bottom:28px}.lesson h1{font-size:32px}.lead{font-size:17px}.activity{padding:18px}.activity-controls{grid-template-columns:1fr;gap:9px}.activity-diagram{height:190px}.knowledge-check{padding:20px}.lesson-finish{flex-direction:column;align-items:flex-start;gap:12px}.equation{font-size:20px;padding:18px}.progress-levels{grid-template-columns:1fr}.course-intro p{font-size:15px}.completion h1,.locked-screen h1{font-size:32px}footer{padding:24px 20px;flex-direction:column;gap:10px}}@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important}}
.activity-diagram{height:auto;min-height:220px}.numeric-value{float:right;width:82px;padding:4px 6px;color:#d3effd;background:#0b1828;border:1px solid #38566e;border-radius:5px;font-size:14px}.numeric-value[aria-invalid=true]{border-color:#e09f81}.activity-controls label{line-height:2.1}.activity-controls input[type=range]{clear:both}.playback{display:flex;gap:15px;align-items:center;margin:0 0 24px;padding:12px;background:#0b1829;border:1px solid #243d55;border-radius:8px}.playback label{font-size:12px;color:#9bb9cf;flex:1}.playback input{display:block;width:100%;accent-color:#6ad6f7}.playback output{min-width:50px;font-size:13px;color:#bbdbed}.compare-actions{display:flex;gap:9px;flex-wrap:wrap;margin-top:19px}.comparison{display:flex;flex-wrap:wrap;gap:10px 20px;margin-top:14px;color:#9ec2d5;font-size:13px;line-height:1.7}.input-feedback{font-size:12px;min-height:20px;margin-top:8px;color:#dfbe98}.activity-result{min-height:92px}.model-note{font-size:13px}.activity-diagram text{font-size:12px}@media(max-width:760px){.activity-diagram{min-height:190px}.activity-controls{gap:16px}.numeric-value{width:90px}}
.comparison>span{flex:1 1 190px}.comparison small{display:block;color:#839eb5;font-size:12px;line-height:1.6;margin-top:4px}
.activity-controls input.numeric-value{display:inline-block;width:90px;margin:0 0 0 8px;cursor:text;clear:none}.activity-controls input[type=range]{width:100%;margin:18px 0 12px}
/* Keep optional practice inside the simulation, with a single clear goal. */
.drag-tip{font-size:12px;color:#8bd2e9;margin:0 0 20px;text-align:center}.drag-tip span{font-size:19px;vertical-align:middle;margin-right:6px}.diagram-handle{cursor:grab;touch-action:none;outline:none}.diagram-handle:hover circle:nth-of-type(2),.diagram-handle:focus circle:nth-of-type(2){fill:#28627a;stroke:#fff;stroke-width:3}.diagram-handle:active{cursor:grabbing}.experiment{padding:20px;margin-top:24px;border:1px solid #345f73;border-radius:10px;background:linear-gradient(120deg,#122d3c,#102331)}.experiment-heading{display:flex;justify-content:space-between;align-items:center;gap:10px}.experiment-heading .kicker{margin:0;font-size:10px;letter-spacing:1.4px}.experiment h4{font:500 19px/1.5 'Space Grotesk',sans-serif;color:#e0f5fe;margin:16px 0 8px}.experiment p{font-size:13px;line-height:1.7}.experiment-actions{display:flex;flex-wrap:wrap;gap:9px;margin:17px 0}.experiment-actions .quiet{min-height:38px}#check-experiment:not(:disabled){background:#1b5263;border-color:#51a3b6;color:#d9f7ff}#experiment-hint{padding:12px;border-left:2px solid #deb77d;color:#e3cfa9;background:#2b2c29;margin-bottom:13px}#experiment-feedback{min-height:44px;color:#a7c1d2}#experiment-feedback.target-reached{color:#97e2bc}.experiment-progress{color:#91c6da;margin-top:10px}@media(max-width:450px){.experiment{padding:16px}.experiment-heading{align-items:flex-start}.experiment-heading .kicker{max-width:150px;line-height:1.7}.experiment h4{font-size:18px}.experiment-actions{gap:8px}.drag-tip{font-size:11px}}
/* Flight school: a calm, playful mission surface, with one idea per stage. */
.flight-invite{display:flex;align-items:center;gap:20px;padding:23px 26px;margin:24px 0;background:linear-gradient(110deg,#173b4b,#12253b);border:1px solid #396575;border-radius:14px}.invite-plane{display:grid;place-items:center;width:56px;height:56px;flex:none;border-radius:15px;background:#215569;color:#b7edfa;font-size:32px;transform:rotate(-12deg)}.flight-invite .kicker{font-size:10px;margin:0 0 7px}.flight-invite strong{font:500 22px 'Space Grotesk',sans-serif}.flight-invite small{display:block;color:#a6c5d7;font-size:13px;margin-top:7px;line-height:1.6}.invite-arrow{margin-left:auto;font-size:28px;color:#90dce9}.flight-page{max-width:1120px;margin:auto}.flight-title{display:flex;align-items:center;justify-content:space-between;gap:24px;margin:35px 0 30px}.flight-title p{margin-top:15px}.wings-emblem{font-size:46px;color:#edc991;background:#342f2d;border:1px solid #786346;display:grid;place-items:center;border-radius:50%;width:84px;height:84px;flex:none}.flight-stages{display:grid;grid-template-columns:repeat(3,1fr);list-style:none;padding:0;margin:0 0 24px;gap:12px}.flight-stages li{display:flex;align-items:center;gap:10px;color:#7f9bb1;font-size:13px;padding:14px;border-bottom:2px solid #253c4e}.flight-stages li>span{display:grid;place-items:center;width:25px;height:25px;border:1px solid #385770;border-radius:50%;flex:none}.flight-stages .current{color:#b9edf7;border-color:#81d3df}.flight-stages .done>span{background:#23594e;border-color:#6bb49b;color:#c4f4dc}.flight-game{border:1px solid #345266;border-radius:18px;overflow:hidden;background:#102233}.mission-brief{padding:26px 30px;border-bottom:1px solid #30485c;display:grid;grid-template-columns:1fr auto;gap:7px 20px}.mission-brief .kicker{grid-column:1/-1;margin:0;font-size:10px}.mission-brief h2{font-size:25px}.mission-brief p{font-size:14px;max-width:370px}.flight-body{display:grid;grid-template-columns:minmax(0,1.3fr) minmax(290px,1fr)}.flight-map{border-right:1px solid #2d4659;background:#0c1f31}.flight-scene{width:100%;display:block}.map-label{font:10px 'DM Sans',sans-serif;letter-spacing:1px;fill:#b4d6e2}.flight-telemetry{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;padding:22px;border-top:1px solid #2d4659}.flight-telemetry small{display:block;font-size:9px;letter-spacing:1px;color:#7bacc4;margin-bottom:8px}.flight-telemetry b{font:500 22px 'Space Grotesk',sans-serif;color:#bce9f6}.flight-console{padding:24px}.prediction .kicker,.flight-controls .kicker{font-size:10px;margin-bottom:10px}.prediction h3{font-size:17px;line-height:1.5}.prediction-options{display:flex;flex-wrap:wrap;gap:7px;margin:14px 0}.prediction-options .quiet{font-size:12px;min-height:36px}.flight-console .chosen,.livery-picker [aria-pressed=true]{background:#24566c;border-color:#7fcce1;color:#ebfbff}#prediction-feedback{font-size:12px;line-height:1.7;color:#9fbdcc;min-height:42px}.flight-controls{border-top:1px solid #2d4659;margin-top:20px;padding-top:20px}.flight-controls label{display:flex;justify-content:space-between;color:#b9d1df;font-size:13px;gap:10px}.flight-controls output{color:#c8effb}.flight-controls input{width:100%;accent-color:#90deed;margin:15px 0 20px;cursor:pointer}.flight-controls input:disabled{opacity:.4;cursor:default}.heading-presets{display:flex;gap:8px;margin-top:-4px}.heading-presets button{flex:1}.control-caption{font-size:11px;line-height:1.6;color:#91adbf;display:block;margin-top:10px}.flight-actions{display:flex;flex-wrap:wrap;gap:9px;margin-top:23px}.flight-actions .primary{width:100%}.flight-actions .quiet{font-size:11px;min-height:34px}#flight-hint-text{font-size:13px;color:#e5c99c;margin-top:15px}.flight-feedback{padding:19px 26px;background:#142b3d;border-top:1px solid #2e495c;color:#abcadb;line-height:1.8;font-size:14px;min-height:64px}.flight-feedback.flight-success{background:#173c35;color:#c6ead7}.flight-bottom{padding:19px 24px;display:flex;justify-content:space-between;align-items:center;gap:15px;border-top:1px solid #2a4255}.flight-bottom span{font-size:11px;color:#90aabd}.flight-model{font-size:12px;line-height:1.8;margin-top:20px;color:#7793a9}.checkpoint-reward{display:flex;align-items:center;gap:20px;padding:25px;background:#152f3a}.checkpoint-reward>span{font-size:37px;color:#e9cc97}.checkpoint-reward>div{flex:1}.checkpoint-reward strong{font:500 20px 'Space Grotesk'}.checkpoint-reward p{font-size:13px;margin-top:5px}.wings-reward{text-align:center;padding:35px;background:radial-gradient(ellipse at top,#3a413b,#142b39 75%)}.earned-wings{font-size:40px;letter-spacing:14px;color:#f1cc88;margin:0 0 18px;animation:earn-wings .6s ease-out}.wings-reward .kicker{color:#e4c798}.wings-reward p{font-size:14px;margin-top:13px}.livery-picker{display:flex;gap:10px;align-items:center;justify-content:center;flex-wrap:wrap;margin:25px 0}.livery-picker>span{width:100%;font-size:12px;color:#c8c0aa}.wings-reward .primary{margin-top:5px}.beacon-active{animation:beacon-glow 1.5s ease-in-out infinite}.badge-earned{color:#e3ca95;font-size:14px;margin-top:14px}@keyframes earn-wings{from{opacity:0;transform:translateY(12px) scale(.85)}to{opacity:1;transform:none}}@keyframes beacon-glow{50%{stroke-opacity:.3}}@media(max-width:950px){.flight-body{grid-template-columns:1fr}.flight-map{border-right:0;border-bottom:1px solid #2d4659}.flight-scene{max-height:390px}.flight-console{display:grid;grid-template-columns:1fr 1fr;gap:20px}.flight-controls{margin:0;border:0;padding:0}.flight-actions,#flight-hint-text{grid-column:1/-1}.flight-actions{margin-top:0}.flight-actions .primary{width:auto}.mission-brief{display:block}.mission-brief h2{margin:10px 0}.mission-brief p{max-width:none}}@media(max-width:600px){.flight-title{gap:15px;margin:26px 0}.flight-title h1{font-size:32px}.flight-title p{font-size:14px}.wings-emblem{width:55px;height:55px;font-size:31px}.flight-stages{gap:5px}.flight-stages li{display:block;font-size:11px;line-height:1.5;padding:9px 4px}.flight-stages li>span{margin-bottom:9px}.mission-brief{padding:22px}.mission-brief h2{font-size:23px}.flight-console{display:block;padding:21px}.flight-controls{margin-top:20px;border-top:1px solid #2d4659;padding-top:20px}.flight-actions{margin-top:22px}.flight-actions .primary{width:100%}.flight-telemetry{padding:17px 14px;gap:7px}.flight-telemetry b{font-size:18px}.flight-telemetry small{font-size:8px;letter-spacing:.6px}.flight-feedback{padding:19px 21px}.flight-bottom{display:block;padding:20px}.flight-bottom span{display:block;margin-top:12px}.checkpoint-reward{flex-wrap:wrap;padding:22px}.checkpoint-reward .primary{width:100%}.flight-invite{padding:20px;gap:15px}.flight-invite strong{font-size:20px}.flight-invite small{font-size:12px}.invite-plane{width:42px;height:42px;font-size:25px}.invite-arrow{font-size:23px}.wings-reward{padding:28px 20px}}@media(prefers-reduced-motion:reduce){.earned-wings,.beacon-active{animation:none}}
.flight-watch{display:flex;align-items:center;gap:12px;justify-content:space-between;padding:16px 22px;border-top:1px solid #2d4659}.flight-watch p{font-size:12px;line-height:1.7;color:#a8c8d7}.flight-watch button{flex:none}.flight-watch [hidden]{display:none}
.topic-map{padding:24px;align-self:start;border-radius:0 0 12px 0}.target-board{display:flex;align-items:center;justify-content:space-between;gap:15px;padding:17px;background:#193d48;border:1px solid #426f75;border-radius:10px;margin-bottom:20px}.target-board small,.topic-readings small{display:block;font-size:10px;letter-spacing:1.2px;color:#a2c2d1;margin-bottom:8px}.target-board b{font:500 23px 'Space Grotesk',sans-serif;color:#c0edcd}.target-board .tag{white-space:nowrap;font-size:10px}.topic-readings{display:grid;grid-template-columns:1fr 1fr;gap:17px;border-top:1px solid #2e4d62;padding-top:22px}.topic-readings strong{font:500 22px 'Space Grotesk',sans-serif;color:#bce4f1}#topic-detail{font-size:12px;margin-top:14px;line-height:1.7}.target-meter{height:7px;background:#263c4e;border-radius:10px;overflow:hidden;margin-top:22px}.target-meter span{display:block;height:100%;background:#79bace;transition:width .15s}.target-meter .on-target{background:#8be0b6}.meter-note{font-size:10px;margin-top:9px;color:#7f9fae}.mission-playback{display:flex;align-items:center;gap:12px;margin-top:20px}.mission-playback label{font-size:11px;flex:1}.mission-playback input{width:100%;display:block;accent-color:#8de1eb}.mission-playback output{font-size:12px}.mission-playback button{min-width:112px}#topic-map-feedback{font-size:13px;line-height:1.8;margin-top:20px;color:#b6d8c8}.topic-input-pair{display:flex;align-items:center;gap:15px}.topic-input-pair input[type=range]{flex:1;min-width:0}.topic-input-pair input[type=number]{width:83px;padding:8px;background:#0b1c2b;color:#d1edf8;border:1px solid #41617a;border-radius:6px;margin:8px 0 16px}.topic-input-pair input[aria-invalid=true]{border-color:#ed998d}.topic-controls label>span{color:#7f9daf;font-size:11px}.topic-input-pair input:disabled{opacity:.55}.topic-controls>div+div{margin-top:13px}#topic-input-feedback{font-size:12px;color:#e4bb93;margin-top:12px}#topic-hint-text{font-size:13px;color:#e4c69c;margin-top:15px}.topic-page .wings-reward .back-link{display:block;margin-top:20px}.mission-passport{display:grid;grid-template-columns:repeat(5,1fr);gap:13px;margin-bottom:35px}.passport-card{display:flex;flex-direction:column;align-items:center;text-align:center;padding:22px 12px;border:1px solid #2c465b;background:#102032;border-radius:12px;gap:12px}.passport-card strong{font:500 16px 'Space Grotesk',sans-serif}.passport-card small{font-size:11px;color:#94aec0;line-height:1.6;flex:1}.passport-icon{font-size:30px;color:#9ee1ec}.passport-card.earned{border-color:#7b7355;background:linear-gradient(145deg,#30342d,#152b35)}.earned .passport-icon{color:#eed19b}.passport-card.locked{opacity:.8}.passport-card:hover:not(.locked){border-color:#78c5d9}.mission-collection h2{font-size:25px}@media(max-width:950px){.topic-map{border-radius:0}.mission-passport{grid-template-columns:repeat(3,1fr)}}@media(max-width:600px){.topic-map{padding:20px}.target-board{align-items:flex-start}.target-board b{font-size:20px}.target-board .tag{max-width:90px;white-space:normal;line-height:1.4}.topic-readings strong{font-size:18px}.topic-readings small{font-size:9px}.mission-passport{grid-template-columns:repeat(2,1fr)}.mission-playback{flex-wrap:wrap}.mission-playback label{min-width:90px}.topic-page h1{font-size:29px}}@media(prefers-reduced-motion:reduce){.target-meter span{transition:none}}
.attempt-coach{display:grid;grid-template-columns:1fr 1.4fr;gap:20px 26px}.attempt-coach .kicker{font-size:10px;margin-bottom:7px;letter-spacing:1.2px}.attempt-coach p{font-size:14px;line-height:1.8;color:#c3d9e5}.attempt-coach .coach-next{padding:15px 18px;background:#123c45;border:1px solid #386572;border-radius:9px;grid-column:1/-1}.coach-next .kicker{color:#a8e1cf}.attempt-comparison{grid-column:1/-1;border-top:1px solid #365365;padding-top:16px}.flight-success .attempt-coach p{color:#c6ead7}.attempt-coach .attempt-comparison p{font-size:13px}@media(max-width:600px){.attempt-coach{grid-template-columns:1fr;gap:18px}.attempt-coach .coach-next{padding:14px}.attempt-coach p{font-size:13px}}

/* Language names stay in their own scripts; the layout accommodates longer labels. */
.language-picker{display:flex;align-items:center;gap:8px;margin-left:auto;color:#a9d7ea;flex-shrink:0}.language-picker select{font:inherit;font-size:13px;color:#d6ebf5;background:#10273a;border:1px solid #39566d;border-radius:9px;padding:9px 28px 9px 10px;max-width:150px;cursor:pointer}.language-picker select:focus-visible{outline:2px solid #8cdef0;outline-offset:3px}.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}.topbar{gap:20px}.topbar nav{flex-wrap:wrap}.primary,.quiet{white-space:normal}.level-info{min-width:0}.lesson-links a{overflow-wrap:anywhere}.activity-diagram text{font-size:11px}html[lang="ru"] .activity-diagram text,html[lang="uz"] .activity-diagram text{font-size:10px}.flight-stages li{overflow-wrap:anywhere}.topbar .header-channel{margin-left:0}@media(max-width:680px){.topbar{flex-wrap:wrap;gap:14px}.topbar nav{order:3;width:100%;justify-content:center;margin:0}.language-picker{margin-left:auto}.topbar .header-channel{display:none}.language-picker select{max-width:140px}.flight-controls label{flex-wrap:wrap}.activity-controls label{min-width:0}.activity-result strong{overflow-wrap:anywhere}.passport-card strong{overflow-wrap:anywhere}}
/* Two experiments share one model, clock and (where applicable) plot scale. */
.comparison-workbench{margin-top:24px;border:1px solid #38566b;border-radius:14px;background:#0c1d2c;overflow:hidden}.comparison-heading{padding:22px 22px 16px}.comparison-heading .kicker{font-size:10px;margin-bottom:8px}.comparison-heading h3{font-size:22px}.comparison-heading p,#comparison-empty p{font-size:13px;line-height:1.7;margin:10px 0;color:#a6c1d2}#comparison-empty{padding:0 22px 22px}#comparison-details>summary{padding:15px 22px;border-top:1px solid #294559;cursor:pointer;color:#bcdfed;font-size:14px}#comparison-details>summary:focus-visible{outline:2px solid #83d6ee;outline-offset:-4px}.comparison-pair{display:grid;grid-template-columns:1fr 1fr;border-top:1px solid #294559}.comparison-case{min-width:0;padding:18px 12px;background:#112637}.reference-case{border-right:1px solid #294559;background:#17232f}.case-heading{display:flex;align-items:center;gap:10px;padding:0 4px;min-height:70px}.case-letter{display:grid;place-items:center;flex:none;width:32px;height:32px;border-radius:9px;background:#274b5e;color:#b1e2f1;font-weight:700}.reference-case .case-letter{background:#414036;color:#e4d6ac}.case-heading h4{font-size:16px;margin:0;line-height:1.5}.case-heading small{font-size:11px;color:#9eb7c8;line-height:1.5;display:block;margin-top:5px}.comparison-case .activity-diagram{width:100%;display:block;min-height:140px}.comparison-case dl{margin:0;display:grid;gap:10px}.comparison-case dl>div,.comparison-inputs label{display:flex;justify-content:space-between;align-items:center;gap:12px;min-height:46px;font-size:12px;padding:4px 8px;color:#bfd1df}.comparison-case dt{flex:1;line-height:1.4}.comparison-case dd{margin:0;font-variant-numeric:tabular-nums;font-size:15px;color:#e5dfce}.comparison-inputs{display:grid;gap:10px}.comparison-inputs input{width:76px;min-width:0;flex-shrink:0;box-sizing:border-box;background:#0c1b2b;border:1px solid #40647e;border-radius:6px;padding:9px 5px;color:#e5f5fc;font:inherit;font-size:14px}.comparison-inputs input:focus-visible{outline:2px solid #85d9ee;outline-offset:2px}.comparison-inputs input[aria-invalid=true]{border-color:#f0a886}.comparison-live{display:block;min-height:36px;padding:12px 8px 0;color:#accdde;font-size:11px;line-height:1.6;font-variant-numeric:tabular-nums}.comparison-playback{display:flex;align-items:center;gap:15px;padding:18px 20px 6px;flex-wrap:wrap}.comparison-playback label{flex:1;min-width:130px;font-size:12px;color:#b4ccda}.comparison-playback input{width:100%;display:block;accent-color:#7bd5ef;margin-top:8px}.comparison-playback output{font-size:13px;color:#cbe4f2}.comparison-note{font-size:12px!important;line-height:1.7!important;color:#92adbf;margin:12px 20px!important}#comparison-changes{font-size:13px;line-height:1.7;margin:18px 20px;padding:12px;border-left:2px solid #8ccde0;background:#142d3f;color:#c4dfeb}.comparison-table-wrap{overflow-x:auto;padding:0 20px 6px}.comparison-table{width:100%;border-collapse:collapse;font-size:12px;font-variant-numeric:tabular-nums}.comparison-table caption{text-align:left;font-size:16px;font-weight:600;padding-bottom:14px;color:#d1e8f4}.comparison-table th,.comparison-table td{text-align:left;padding:11px 8px;border-bottom:1px solid #294559;line-height:1.5}.comparison-table th{font-weight:500;color:#acc7d8}.comparison-table thead th{font-size:11px}.comparison-table .changed-value{color:#a1e4f1;font-weight:600}#comparison-details>[data-compare-save]{margin:8px 20px 20px}#comparison-input-error,#comparison-save-status{font-size:13px;line-height:1.6;margin:0 20px;color:#d8bc94}#comparison-input-error:not(:empty),#comparison-save-status:not(:empty){padding:12px 0}#comparison-details[hidden],#comparison-empty[hidden]{display:none}@media(max-width:600px){.comparison-pair{grid-template-columns:1fr}.reference-case{border-right:0;border-bottom:1px solid #294559}.comparison-case{padding:14px}.case-heading{min-height:55px}.comparison-case .activity-diagram{max-height:220px}.comparison-heading{padding:20px 18px 12px}.comparison-heading h3{font-size:20px}.comparison-table-wrap{padding:0 12px 6px}.comparison-table{font-size:11px}.comparison-table th,.comparison-table td{padding:8px 4px}.comparison-playback{gap:12px}.comparison-live:empty{display:none}}

html .comparison-case.motion-comparison .activity-diagram text{font-size:17px}

/* cockpit.css */
/* AeroLab flight deck: a quiet cabin surrounding the learning instruments. */
:root{--bg:#070f19;--panel:#122331;--line:#304653;--muted:#a7bac8;--text:#edf5f6;--cyan:#91dfeb}
body{background:radial-gradient(ellipse at 0 300px,#15313b70,transparent 60%),radial-gradient(ellipse at 100% 650px,#2b302c55,transparent 60%),#070f19}
body::before{content:"";position:fixed;inset:0;pointer-events:none;z-index:-1;background-image:linear-gradient(#6faabb04 1px,transparent 1px),linear-gradient(90deg,#6faabb04 1px,transparent 1px);background-size:48px 48px}
.flight-deck{max-width:1440px;margin:18px auto 0;padding:0 24px}
.canopy{height:206px;position:relative;display:flex;align-items:flex-end;justify-content:space-between;padding:34px 48px 28px;gap:25px;background:linear-gradient(0deg,#071420b8 0%,#07142020 62%,#0a142008),url('assets/cockpit-sky.svg') center 46%/cover;border:1px solid #57717c;border-bottom:0;border-radius:90px 90px 0 0;box-shadow:inset 0 2px 0 #b1c5c435,inset 0 10px 20px #030c1660;overflow:hidden}
.canopy::after{content:"";position:absolute;inset:8px;border:1px solid #d2e7e914;border-radius:80px 80px 0 0;pointer-events:none}
.canopy-copy{position:relative;z-index:1;text-shadow:0 2px 12px #06111a}
.canopy-copy .kicker{font-size:10px;letter-spacing:2.6px;color:#d0e6e9;margin-bottom:12px}
.canopy-copy p{font:500 clamp(22px,2.5vw,34px)/1.25 'Space Grotesk',sans-serif;letter-spacing:-.8px;color:#f0f5ef;max-width:500px}
.journey-instrument{position:relative;z-index:1;min-width:188px;padding:18px 22px;border:1px solid #57717785;border-radius:12px;background:#06141fde;box-shadow:0 8px 26px #030b1333,inset 0 1px 0 #ffffff12}
.journey-instrument .kicker{font-size:9px;letter-spacing:1.7px;color:#a4c7ca;margin:0 15px 8px 0}
.journey-instrument strong{font:500 23px 'Space Grotesk',sans-serif;letter-spacing:-.6px;color:#e3ebe6}
.instrument-light{position:absolute;right:14px;top:18px;width:5px;height:5px;border-radius:50%;background:#a2dcbc;box-shadow:0 0 9px #a2dcbc80}
.journey-meter{height:3px;background:#263d47;border-radius:4px;margin-top:12px;overflow:hidden}
.journey-meter span{display:block;height:100%;background:#a0dbd2;transition:width .45s ease}
.topbar{max-width:none;margin:0;padding:13px 28px;gap:24px;min-height:80px;background:linear-gradient(#20313d,#12222f);border:1px solid #405461;border-top-color:#6c8085;border-radius:0 0 18px 18px;box-shadow:0 16px 40px #02081066,inset 0 1px 0 #a1c2c014;position:relative;z-index:5}
.brand{font-size:24px;flex:none;text-shadow:0 1px 4px #050e18}
.brand svg{width:30px}
.topbar nav{gap:5px;padding:4px;background:#07141fc7;border:1px solid #354854;border-radius:10px;margin:0}
.topbar nav a{position:relative;display:flex;gap:9px;align-items:center;justify-content:center;min-height:42px;padding:10px 15px;border-radius:7px;color:#a6bcc8;font-size:13px;border:1px solid transparent;transition:background .2s,color .2s,border-color .2s,box-shadow .2s}
.nav-number{font-size:9px;letter-spacing:1px;color:#71929f;font-variant-numeric:tabular-nums}
.topbar nav a:hover{background:#223845;color:#e3f4f6}
.topbar nav a[aria-current]{background:linear-gradient(135deg,#254c56,#1a3644);border-color:#5b8993;color:#def7f6;box-shadow:inset 0 1px 0 #b6f4f121,0 2px 8px #020a1540}
.topbar nav a[aria-current]::after{content:"";position:absolute;bottom:-5px;left:35%;right:35%;height:2px;background:#b2eee6;box-shadow:0 0 8px #9aefeb80}
.topbar nav a[aria-current] .nav-number{color:#9fe1dd}
.language-picker select{background:#101e29;border-color:#415864;min-height:42px;max-width:132px;color:#c8dee5}
.header-channel{font-size:12px;line-height:1.5;max-width:100px;color:#b8c9ce}
.header-channel span{color:#d8c194}
main{max-width:1220px;padding:46px 36px 70px;scroll-margin-top:20px;view-transition-name:learning-panel}
main:focus,h1:focus{outline:none}
.skip-link{position:fixed;left:24px;top:-100px;z-index:50;padding:14px 20px;background:#d5f5f0;color:#09212d;border-radius:8px}
.skip-link:focus{top:15px}
h1{letter-spacing:-1.6px;color:#eff6f5}
.kicker{color:#9bc8ce;font-size:10px;letter-spacing:2px}
.course-intro{margin-bottom:32px}
.course-intro h1{max-width:850px}
.current-card{border-color:#4a6471;border-radius:22px;background:#162d3c;box-shadow:0 16px 45px #0208123d,inset 0 1px 0 #d0e4e314}
.current-copy{padding:38px}
.current-copy h2{font-size:34px}
.current-art{background-image:linear-gradient(90deg,#162d3c,transparent 45%),url('assets/hero.png')}
.tag{border-color:#405d69;background:#152f3b;color:#b8d7dc;letter-spacing:1px;border-radius:4px}
.primary{min-height:46px;border-radius:9px;background:linear-gradient(135deg,#acdeda,#83c5d4);border-color:#c3eee4;color:#0b2934;box-shadow:inset 0 1px 0 #ffffff60,0 4px 14px #010b1640;transition:transform .2s,box-shadow .2s,background .2s}
.primary:hover:not(:disabled){background:linear-gradient(135deg,#c2eee7,#9ddbe6);color:#092832;box-shadow:0 5px 20px #7ed9da22;transform:translateY(-2px)}
.primary:active:not(:disabled){transform:translateY(0)}
.quiet{background:linear-gradient(#203544,#162937);border-color:#3b5665;color:#bbdfe8;min-height:36px;transition:background .2s,border-color .2s,transform .2s}
.quiet:hover:not(:disabled){background:#294653;border-color:#92c3cb}
a:focus-visible,button:focus-visible,summary:focus-visible,input:focus-visible,select:focus-visible{outline:2px solid #c4eade;outline-offset:4px}
.lesson-top{padding:14px 18px;border:1px solid #2d4552;border-radius:10px;background:#11222bba;margin-bottom:34px}
.lesson-layout{grid-template-columns:minmax(0,1fr) 265px;gap:32px}
.lesson h1{font-size:clamp(31px,3.2vw,42px)}
.lead{color:#c2d2da}
.flight-invite{background:linear-gradient(115deg,#203f48,#152936);border-color:#496974;box-shadow:inset 0 1px 0 #b8e3dc12;border-radius:14px;transition:transform .22s,border-color .22s,box-shadow .22s}
.flight-invite:hover{transform:translateY(-3px);border-color:#84b5bb;box-shadow:0 8px 22px #0004}
.invite-plane{background:#315964;border:1px solid #63828b;color:#d6f0ed;border-radius:12px}
.invite-arrow{color:#d6c096}
.example{border-color:#a9ba93}
.example .kicker{color:#d1c5a9}
.equation{background:linear-gradient(110deg,#19303b,#102630);border-color:#456370;color:#b9e6e7;border-radius:12px;box-shadow:inset 0 0 22px #03101850}
.activity,.knowledge-check,.flight-game{background:linear-gradient(125deg,#142a36,#101f2d);border-color:#46606d;border-radius:17px;box-shadow:0 12px 32px #01091230,inset 0 1px 0 #bacbd61a;position:relative}
.activity::before,.activity::after{content:"";position:absolute;top:10px;width:5px;height:5px;background:#17232d;border:1px solid #617581;border-radius:50%;box-shadow:inset 0 1px 2px #0008}
.activity::before{left:10px}.activity::after{right:10px}
.activity>header{border-bottom:1px solid #2e4956;padding:6px 0 19px}
.activity-diagram{background:radial-gradient(ellipse at center,#152f3a55,transparent 70%)}
.activity-controls{padding:18px;border:1px solid #2d4856;background:#0a1a25;border-radius:11px}
.activity-result{padding:20px 0 4px;border-top:0}
.activity-result strong{color:#b3e8da;font-variant-numeric:tabular-nums}
.experiment{background:linear-gradient(110deg,#1b3640,#142b36);border-color:#46636b}
.video-card{background:linear-gradient(140deg,#1b2b36,#11202d);border-color:#354e5d;box-shadow:inset 0 1px 0 #bed8e110}
.video-icon{background:#3d3330;border:1px solid #6b5342;color:#e4c199}
.video-card .kicker{color:#c7b596}
.level-summary{padding:24px 18px;margin-top:18px;border:1px solid #2e4654;border-radius:12px;background:#11222bc9}
.level-summary ol{padding-left:18px}
.level-summary .selected{color:#b4e5de}
.level-row{background:linear-gradient(120deg,#142733,#10202c);border-color:#324d5c;border-radius:14px;transition:border-color .2s,transform .2s}
.level-row:not(.locked):hover{border-color:#658b96;transform:translateX(3px)}
.level-row.current{background:linear-gradient(110deg,#1c3942,#142a37);border-color:#648b91;box-shadow:inset 3px 0 #aadbcf}
.level-number{background:#0b1d29;border:1px solid #537681;box-shadow:inset 0 0 0 4px #192e3a;color:#b5e9e2}
.locked .level-number{box-shadow:inset 0 0 0 4px #12202b}
.level-row.locked{background:#0e1c27}
.lesson-links a{border-color:#3b5766;border-radius:7px}
.lesson-links .next-lesson{background:#254b55;color:#d6f2eb;border-color:#6c969a}
.takeaway{background:linear-gradient(100deg,#203b39,#152d31);border-color:#a5ceae}
.takeaway .kicker{color:#b6d7b9}
.answers button{background:#0c1e2b;border-color:#3c5464;transition:background .2s,border-color .2s}
.answers button:hover:not(:disabled){background:#1e3b46;border-color:#93bec1}
.passport-card{background:linear-gradient(135deg,#1b303e,#10212f);border-color:#3a5463;transition:transform .2s,border-color .2s}
.passport-card:hover:not(.locked){transform:translateY(-3px)}
.passport-card.earned{background:linear-gradient(145deg,#383f32,#18323b);border-color:#8f8e64}
.progress-levels section,.next-card{background:linear-gradient(135deg,#192f3c,#10212f);border-color:#3d5868;border-radius:14px}
.progress-track{height:7px;background:#263b46}.progress-track div{background:linear-gradient(90deg,#8dc9d2,#c1d8ac)}
.completion-check{border:1px solid #789d87;background:radial-gradient(circle,#2b5147,#15332f);color:#c0e7c7;box-shadow:0 0 0 8px #789d870d}
.comparison-workbench{border-color:#486470;background:#0e222d}
.reference-case{background:#262e30}.reference-case .case-letter{background:#4a4936;color:#e8dab4}
.comparison-case:not(.reference-case){background:#193440}
footer{color:#8da5b2;border-color:#2b414e}
/* Only the content panel changes; controls, sky, and navigation keep their place. */
::view-transition-old(root),::view-transition-new(root){animation:none}
::view-transition-group(learning-panel){animation-duration:320ms;animation-timing-function:cubic-bezier(.2,.7,.2,1)}
::view-transition-old(learning-panel){animation:panel-out 180ms ease both}
::view-transition-new(learning-panel){animation:panel-in 320ms cubic-bezier(.2,.7,.2,1) both}
@keyframes panel-out{to{opacity:0;transform:translateY(-8px)}}
@keyframes panel-in{from{opacity:0;transform:translateY(18px)}to{opacity:1;transform:translateY(0)}}
@media(min-width:1600px){.flight-deck{margin-top:26px}.canopy{height:230px}}
@media(max-width:1100px){.topbar{gap:14px;padding:13px 20px}.topbar nav a{padding:10px 12px}.header-channel{display:none}.lesson-layout{gap:24px;grid-template-columns:minmax(0,1fr) 240px}.canopy{padding:30px 35px}.nav-number{display:none}}
@media(max-width:760px){.flight-deck{padding:0 14px;margin-top:12px}.canopy{height:170px;padding:26px 25px 22px;border-radius:45px 45px 0 0;background-position:50% 50%}.canopy::after{border-radius:40px 40px 0 0}.canopy-copy p{font-size:24px;max-width:260px}.canopy-copy .kicker{font-size:8px;letter-spacing:1.6px}.journey-instrument{min-width:155px;padding:14px 16px}.journey-instrument strong{font-size:20px}.journey-instrument .kicker{font-size:8px;letter-spacing:1px}.topbar{flex-wrap:wrap;gap:12px;padding:15px 18px;border-radius:0 0 16px 16px}.topbar nav{order:3;width:100%;display:grid;grid-template-columns:repeat(3,1fr)}.topbar nav a{padding:8px;font-size:12px;min-height:42px}.brand{font-size:23px}.brand svg{height:30px}.language-picker select{min-height:36px}.language-picker{margin-left:auto}.lesson-layout{display:flex}.lesson-aside{position:static}.lesson h1{font-size:32px}main{padding:30px 22px 50px}.lesson-top{padding:12px;font-size:11px;gap:10px;flex-wrap:wrap}.lesson-top .back-link{font-size:12px}.activity{padding:18px 14px}.activity-controls{padding:14px}.current-copy{background:linear-gradient(90deg,#162d3cf5,#12243acc),url('assets/hero.png') center/cover}.current-copy h2{font-size:29px}}
@media(max-width:470px){.canopy{height:155px;padding:24px 20px;gap:10px}.canopy-copy p{font-size:21px;max-width:170px}.canopy-copy .kicker{font-size:7px;letter-spacing:1.3px}.journey-instrument{min-width:112px;max-width:134px;padding:12px}.journey-instrument .kicker{font-size:7px;letter-spacing:.8px;margin-right:3px;line-height:1.6}.instrument-light{display:none}.journey-instrument strong{font-size:17px}.journey-meter{margin-top:9px}.topbar{padding:13px 12px}.topbar nav a{font-size:11px;padding:8px 5px}.language-picker select{max-width:122px}.current-copy{padding:26px}.level-row{padding:20px 14px;gap:12px}.level-row>.tag{font-size:8px;letter-spacing:.4px}.lesson-top span:last-child{margin-left:0}.section-title{gap:12px}.section-title h2{font-size:22px}}
@media(prefers-reduced-motion:reduce){*,*::before,*::after{animation:none!important;transition:none!important;scroll-behavior:auto!important}::view-transition-group(*),::view-transition-old(*),::view-transition-new(*){animation:none!important}.primary:hover:not(:disabled),.flight-invite:hover,.level-row:not(.locked):hover,.passport-card:hover:not(.locked){transform:none}}

/* flight-lab.css */
/* Photographic flight deck and live ground-roll laboratory. */
.canopy{height:290px;border-radius:28px 28px 0 0;background:linear-gradient(90deg,#07131d70,transparent 58%),linear-gradient(0deg,#071420ed,transparent 65%),url('assets/cockpit-photo.png') center 45%/cover;padding:42px 48px;border-color:#5a6367}
.canopy::after{border-radius:22px 22px 0 0}.canopy-copy p{font-size:clamp(27px,3.2vw,44px);max-width:500px}.canopy-copy .kicker{color:#e6d3b1;letter-spacing:3px}.journey-instrument{background:#081621dc;backdrop-filter:blur(12px);border-color:#b7c4b64a}.topbar{background:linear-gradient(#273540,#101f2a);box-shadow:0 18px 45px #0006}.topbar nav a{padding:10px 12px}.topbar .header-channel{display:none}.topbar{gap:22px}.brand{margin-right:10px}.current-card{box-shadow:0 24px 50px #0004}.current-copy{background:radial-gradient(ellipse at top left,#34617040,transparent 85%)}.course-intro h1{font-size:clamp(35px,4vw,52px)}.flight-invite{border-color:#63848b}.runway-invite{display:block;position:relative;overflow:hidden;border:1px solid #7b8b88;border-radius:18px;padding:34px;margin-top:26px;background:linear-gradient(90deg,#10232ef5,#10232ead 65%,#10232e50),url('assets/cockpit-photo.png') center 50%/cover;transition:transform .2s,border-color .2s}.runway-invite:hover{transform:translateY(-3px);border-color:#c7d4b4}.runway-invite .kicker{color:#e1c297}.runway-invite h2{font-size:29px;color:#eaf4f2}.runway-invite p{margin:12px 0 22px;max-width:450px;color:#c5d7df}.runway-invite .primary{gap:28px}.lab-heading{display:flex;justify-content:space-between;align-items:end;gap:25px;margin-bottom:30px}.lab-heading h1{font-size:clamp(32px,3.5vw,46px)}.lab-heading p{margin-top:15px}.lab-heading .back-link{white-space:nowrap;margin-bottom:8px}.lab-heading .kicker{color:#dbbf96}.runway-lab{background:#10222f;border:1px solid #456170;border-radius:18px;overflow:hidden;box-shadow:0 24px 55px #0005}.lab-toolbar{display:flex;align-items:center;justify-content:space-between;gap:16px;padding:17px 22px;background:linear-gradient(#263c49,#172c38);border-bottom:1px solid #4a606b}.lab-live{display:flex;align-items:center;gap:10px;font:600 11px 'Space Grotesk',sans-serif;letter-spacing:2px;color:#dcebdc}.lab-live i{width:6px;height:6px;border-radius:50%;background:#b7ddbb;box-shadow:0 0 10px #b7ddbb80}.lab-view{display:flex;gap:7px}.lab-view .quiet,.lab-speed-selector .quiet{font-size:11px}.runway-lab [aria-pressed=true]{background:#315763;border-color:#94c6c5;color:#e9f6f3}.lab-grid{display:grid;grid-template-columns:minmax(0,1fr) 305px}.lab-stage{min-width:0;background:#0a1d29;border-right:1px solid #3b5765}.runway-scene{display:block;width:100%;background:#1e4555}.runway-scene text{font:12px 'DM Sans',sans-serif;fill:#d7e4df}.runway-scene .scene-value{font-size:15px;fill:#f0e7d5}.lab-instruments{display:grid;grid-template-columns:repeat(4,1fr);gap:1px;background:#354b55;border-block:1px solid #385362}.lab-instruments>div{padding:20px 14px;background:radial-gradient(ellipse at top,#193945,#0c212d);text-align:center}.lab-instruments span{display:block;font-size:10px;color:#9ebfc8;margin-bottom:11px;line-height:1.4}.lab-instruments strong{display:inline-block;font:500 29px 'Space Grotesk',sans-serif;color:#d4efe6;font-variant-numeric:tabular-nums}.lab-instruments small{display:block;font-size:10px;color:#829ca9;margin-top:5px}.lab-playback{padding:24px 20px 12px;display:flex;align-items:center;gap:14px;flex-wrap:wrap}.lab-playback .primary{font-size:13px;min-width:108px}.lab-playback label{flex:1;min-width:110px;color:#a9c5d0;font-size:10px}.lab-playback input{display:block;width:100%;accent-color:#c3dfca;margin-top:10px}.lab-playback output{font:13px 'Space Grotesk',sans-serif;color:#d4e6eb;min-width:42px}.lab-playback .quiet{font-size:11px}.lab-speed-selector{display:flex;gap:6px;align-items:center;padding:0 20px 10px}.lab-speed-selector>span{font-size:10px;color:#9fb5bf;margin-right:8px}.lab-speed-selector .quiet{min-height:29px;padding:4px 10px}.lab-status{margin:10px 20px 22px;padding:14px 17px;background:#183a3e;border-left:2px solid #9dc5ad;border-radius:0 8px 8px 0;font-size:13px;min-height:68px;color:#c0ded3}.lab-settings{padding:25px;background:linear-gradient(135deg,#1a303c,#112432)}.lab-settings h2{font-size:22px;line-height:1.4;margin-bottom:19px}.lab-presets{display:grid;grid-template-columns:1fr 1fr;gap:7px;margin-bottom:25px}.lab-presets .quiet{font-size:11px;min-height:38px}.lab-control{margin-top:20px}.lab-control>label{font-size:12px;color:#b9d0dc}.lab-control>div{display:flex;align-items:center;gap:12px;margin-top:9px}.lab-control input[type=range]{min-width:0;flex:1;accent-color:#a5d5db}.lab-control input[type=number]{width:79px;min-width:0;background:#091c29;border:1px solid #4e6b7a;border-radius:7px;color:#e8f1ee;padding:8px;font-size:13px}.lab-control input[aria-invalid=true]{border-color:#f4aa8b}.lab-control-note{font-size:11px;line-height:1.65;margin-top:14px}.lab-prediction{padding:16px;background:#29342f;border:1px solid #5c6250;border-radius:10px;margin-top:22px}.lab-prediction .kicker{font-size:9px;color:#d9c499;letter-spacing:1px}.lab-prediction p{font-size:12px;line-height:1.7;color:#d2d5c0}#lab-input-error{font-size:12px;line-height:1.6;color:#f1c0a4;margin-top:10px}.lab-analysis{display:grid;grid-template-columns:minmax(0,1.7fr) minmax(240px,1fr);gap:30px;padding:26px;border-top:1px solid #3c5865;background:#102431}.lab-analysis .section-title{margin:0 0 10px;align-items:start;flex-wrap:wrap;gap:12px}.lab-analysis h3{font-size:17px}.lab-legend{display:flex;align-items:center;gap:6px;font-size:10px;color:#a5c0cc}.lab-legend i{height:3px;width:12px;background:#8edde8}.lab-legend i:nth-of-type(2){background:#e9bd8c;margin-left:8px}.lab-chart{width:100%;display:block}.lab-chart text{font:11px 'DM Sans',sans-serif;fill:#a9c7d6}.lab-force-readings h3{margin-bottom:15px}.lab-force-readings>div{display:flex;justify-content:space-between;gap:15px;padding:9px 0;border-bottom:1px solid #304956;font-size:12px;color:#a8c4cf}.lab-force-readings strong{color:#d2e8dd;font:500 14px 'Space Grotesk',sans-serif}.lab-force-readings p{font-size:11px;color:#cfb995;margin-top:15px;line-height:1.6}.lab-assumptions{padding:21px 26px;border-top:1px solid #3c5865;background:#0d1f2b}.lab-assumptions summary{cursor:pointer;font-size:13px;color:#b7d9e2}.lab-assumptions p{margin:16px 0;font-size:12px;max-width:950px}.lab-assumptions a{font-size:12px;color:#a2d5df;display:inline-block;margin:0 20px 8px 0}
@media(min-width:1600px){.canopy{height:320px}}
@media(max-width:1100px){.topbar{gap:12px}.topbar nav a{padding:10px}.lab-grid{grid-template-columns:minmax(0,1fr) 270px}.lab-settings{padding:22px 18px}.lab-instruments strong{font-size:24px}.lab-playback{gap:10px}.lab-playback #lab-reset{order:4}.lab-heading{display:block}.lab-heading .back-link{display:inline-block;margin-top:16px}}
@media(max-width:850px){.lab-grid{grid-template-columns:1fr}.lab-stage{border-right:0}.lab-settings{display:grid;grid-template-columns:1fr 1fr;gap:0 25px;border-top:1px solid #3b5765;padding:24px}.lab-settings>.kicker,.lab-settings>h2,.lab-presets,.lab-control-note,#lab-input-error,.lab-prediction{grid-column:1/-1}.lab-presets{grid-template-columns:repeat(4,1fr);margin-bottom:0}.lab-control{margin-top:18px}.lab-analysis{grid-template-columns:1fr}.lab-instruments strong{font-size:29px}.lab-prediction{margin-top:14px}.brand{margin-right:0}.topbar nav a{font-size:12px;padding:10px 8px}.topbar{gap:10px}.language-picker select{max-width:120px}}
@media(max-width:760px){.canopy{height:220px;padding:26px 23px;background-position:58% center}.canopy-copy p{font-size:25px;max-width:240px}.canopy-copy .kicker{font-size:8px;letter-spacing:1.5px}.topbar nav{grid-template-columns:repeat(4,1fr)}.topbar nav a{font-size:11px}.lab-heading h1{font-size:32px}.lab-heading p{font-size:15px}.runway-invite{padding:25px}.runway-invite h2{font-size:25px}.current-copy{background:linear-gradient(90deg,#132d3df0,#132d3dba),url('assets/hero.png') center/cover}.lab-toolbar{padding:13px;gap:10px;flex-wrap:wrap}.lab-live{font-size:9px;letter-spacing:1px}.lab-toolbar>.tag{display:none}.lab-view .quiet{font-size:10px;padding:7px}.lab-instruments>div{padding:15px 7px}.lab-instruments span{font-size:9px;min-height:25px}.lab-instruments strong{font-size:23px}.lab-settings{padding:20px;gap:0 16px}.lab-control>label{font-size:11px}.lab-control>div{flex-wrap:wrap;gap:8px}.lab-control input[type=range]{width:100%;flex:auto}.lab-control input[type=number]{width:100%}.lab-analysis{padding:20px;gap:20px}.lab-assumptions{padding:20px}.lab-playback{padding:20px 15px 10px}.lab-status{margin:10px 15px 18px}.lab-speed-selector{padding-left:15px}.lab-presets{grid-template-columns:1fr 1fr}}
@media(max-width:470px){.canopy{height:200px;padding:24px 20px;align-items:flex-end}.canopy-copy p{font-size:23px;max-width:175px}.journey-instrument{padding:12px 10px;min-width:105px;max-width:125px}.canopy-copy .kicker{max-width:150px;line-height:1.8}.topbar nav a{font-size:10px;padding:8px 4px}.language-picker select{max-width:120px}.lab-playback .primary{min-width:96px;padding:12px}.lab-playback output{min-width:38px}.lab-settings h2{font-size:21px}}
@media(prefers-reduced-motion:reduce){.runway-invite:hover{transform:none}}

.lab-range{float:right;color:#7fa1af;font-size:10px;margin-top:3px}.lab-force-legend{font-size:11px;line-height:1.6;padding:12px 20px;background:#152d39;color:#bfd8d9}.lab-force-legend[hidden]{display:none}

/* physics-track.css */
.physics-invite{background:radial-gradient(ellipse at 85% 50%,#376f7255,transparent 60%),linear-gradient(110deg,#15313d,#132634)}.physics-invite::after{content:'∿';position:absolute;right:9%;top:0;font:180px 'Space Grotesk',sans-serif;color:#94dfdd12;pointer-events:none}.physics-cards{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px}.physics-topic-card{display:block;padding:25px;border:1px solid #426573;border-radius:16px;background:linear-gradient(130deg,#1d3945,#102633);transition:transform .2s,border-color .2s}.physics-topic-card:hover:not(.locked){border-color:#a4d1cc;transform:translateY(-3px)}.physics-symbol{display:grid;place-items:center;width:56px;height:56px;border-radius:14px;background:#244954;color:#b7e4db;font:36px 'Space Grotesk',sans-serif;flex:none;border:1px solid #53818b}.physics-topic-card>.tag{float:right;margin-top:-46px}.physics-topic-card h3{margin:23px 0 12px;font-size:22px}.physics-topic-card p{font-size:13px;line-height:1.8;margin-bottom:20px}.physics-topic-card.locked{background:#112330;border-color:#304b5b}.physics-topic-card.locked .physics-symbol{background:#1b3340;color:#8fa8b3;border-color:#3a5462}.physics-topic-card .subtle{font-size:12px;color:#b5d8d5}.physics-lesson-heading{display:flex;align-items:start;gap:24px;margin:30px 0}.physics-lesson-heading h1{margin-bottom:19px}.physics-lesson-heading .lead{max-width:850px}.physics-experiment{background:#122b37;border:1px solid #4c6e7b;border-radius:18px;overflow:hidden;box-shadow:0 15px 45px #0003}.physics-experiment-grid{display:grid;grid-template-columns:minmax(0,1fr) 310px}.physics-experiment-grid>div{min-width:0}.physics-scene{width:100%;display:block}.physics-scene text{fill:#b9d6df;font:12px 'DM Sans',sans-serif}.physics-instruments{grid-template-columns:repeat(3,1fr)}.physics-experiment .lab-settings{border-left:1px solid #3f5f6b}.physics-prompt{font-size:13px;line-height:1.8;margin-bottom:12px;color:#b8d0d9}.physics-experiment .model-note{padding:20px 25px;margin:0;border-top:1px solid #355362;background:#0e222e;color:#abc4cf}.physics-experiment .lab-settings button{margin:17px 6px 0 0}#physics-input-error,#physics-save-status{font-size:12px;color:#ecc39b;margin-top:12px;line-height:1.7}#physics-save-status:empty{display:none}#physics-save-status{padding:0 25px 18px}#physics-reference{padding:24px;border-top:1px solid #496674;background:#242f32}#physics-reference p{font-size:12px;margin-top:10px}#physics-reference .physics-scene{margin:20px auto 0;max-width:700px;border-radius:12px}#physics-reference .physics-instruments{max-width:700px;margin:auto}#physics-reference[hidden]{display:none}.physics-resources{margin-top:26px}.physics-resources p{font-size:13px}.physics-resources a{margin-right:24px}.physics-progress-link{display:flex;align-items:center;gap:22px;border:1px solid #487079;background:#1a3540;border-radius:12px;padding:23px;margin-bottom:30px}.physics-progress-link>span:last-child{margin-left:auto;color:#c0e8dd;font-size:13px}.topbar nav a{padding:10px}.topbar{gap:18px}.nav-number{display:none}
@media(max-width:1100px){.topbar{flex-wrap:wrap}.topbar nav{order:3;width:100%;justify-content:space-between}.topbar nav a{flex:1}.language-picker{margin-left:auto}.physics-cards{grid-template-columns:repeat(2,minmax(0,1fr))}.physics-experiment-grid{grid-template-columns:minmax(0,1fr) 260px}}
@media(max-width:760px){.topbar nav{display:flex;overflow-x:auto;justify-content:flex-start;flex-wrap:nowrap}.topbar nav a{flex:1 0 auto;min-width:85px;font-size:11px}.physics-cards{grid-template-columns:1fr}.physics-topic-card{padding:23px}.physics-topic-card h3{margin-top:17px}.physics-experiment-grid{grid-template-columns:1fr}.physics-experiment .lab-settings{border-left:0;border-top:1px solid #3f5f6b;display:block}.physics-experiment .lab-control>div{flex-wrap:nowrap}.physics-experiment .lab-control input[type=number]{width:95px}.physics-lesson-heading{gap:16px}.physics-lesson-heading .physics-symbol{width:44px;height:44px;font-size:27px}.physics-lesson-heading h1{font-size:29px}.physics-lesson-heading .lead{font-size:15px}.physics-instruments strong{font-size:23px}.physics-experiment .lab-playback{gap:12px}.physics-progress-link{flex-wrap:wrap;gap:14px}.physics-progress-link>span:last-child{margin-left:0;width:100%}}
@media(prefers-reduced-motion:reduce){.physics-topic-card:hover:not(.locked){transform:none}}

.physics-reference-settings{display:flex;gap:12px 26px;flex-wrap:wrap;margin-top:18px;font-size:12px;color:#c7d4cb}.physics-reference-settings strong{color:#e8d4af}

/* accounts.css */
.account-heading,.account-hero{margin:36px 0}.account-heading h1,.account-hero h1{font-size:clamp(2rem,4vw,3.6rem);line-height:1.12;letter-spacing:-.04em;margin:16px 0}.account-grid{display:grid;grid-template-columns:1fr 1fr;gap:24px}.account-panel,.account-feature-grid article,.account-metrics article{border:1px solid #36505e;border-radius:20px;background:linear-gradient(140deg,#203540e8,#101e28e8);padding:28px;min-width:0}.account-panel h2{margin-top:0;font-size:1.4rem}.account-panel p,.account-hero p{color:#bed0d5;line-height:1.7}.account-panel form{display:grid;gap:12px;margin:24px 0}.account-panel label{display:block;font-size:.86rem;margin-top:12px;color:#d2e4e5}.account-panel input{box-sizing:border-box;width:100%;min-width:0;padding:14px;border:1px solid #4b6675;border-radius:10px;background:#0a1721;color:#e8f3f0;font:inherit}.account-panel input:focus{outline:2px solid #a5dadf;outline-offset:3px}.account-panel button{min-height:44px}.account-panel [hidden]{display:none!important}.account-panel .primary{justify-self:start}.account-side{background:radial-gradient(at 80% 10%,#32677255,transparent 60%),#101e28}.account-orbit{font-size:3rem;color:#aadbdc}.account-metrics{display:grid;grid-template-columns:repeat(3,1fr);gap:18px;margin:24px 0}.account-metrics article{padding:22px}.account-metrics strong{display:block;font-size:2rem;line-height:1.5}.account-metrics strong small{font-size:1rem;color:#9eb8c2;font-weight:400}.account-metrics span{font-size:.82rem;color:#bad0d8}.account-actions{display:flex;flex-wrap:wrap;gap:10px}.guest-import{border-top:1px solid #36505e;margin-top:28px;padding-top:20px}.account-invite{display:flex;align-items:center;gap:24px;border:1px solid #476775;border-radius:18px;padding:24px;margin:24px 0;background:linear-gradient(110deg,#274954,#192832);text-decoration:none;color:#e5f4ed}.account-invite strong{font-size:1.3rem}.account-invite p{margin:6px 0;color:#bfd3d7}.account-invite>span:last-child{margin-left:auto;font-size:2rem}.account-feature-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px;margin:34px 0}.account-feature-grid article>span{font-size:2.4rem;color:#aadbdc}.account-feature-grid h2{font-size:1.25rem}.joined-class{display:flex;justify-content:space-between;align-items:center;gap:12px;padding:16px 0;border-bottom:1px solid #36505e}.joined-class strong{overflow-wrap:anywhere}.teacher-entry{display:flex;justify-content:space-between;border:1px solid #91cbd0;border-radius:12px;padding:18px;margin-top:24px;color:#b8e4e5;text-decoration:none}.teacher-heading{display:flex;justify-content:space-between;align-items:center;gap:18px}.teacher-layout{display:grid;grid-template-columns:290px minmax(0,1fr);gap:24px}.class-choice{display:flex;justify-content:space-between;gap:12px;width:100%;padding:16px;margin:8px 0;border:1px solid #45616d;border-radius:10px;background:#142632;color:#d8e8e6;text-align:left;font:inherit;overflow-wrap:anywhere}.class-choice[aria-pressed=true]{background:#335765;border-color:#a1dadd}.class-detail-head{display:flex;justify-content:space-between;align-items:center;gap:18px}.class-detail-head h2{margin:10px 0;overflow-wrap:anywhere}.class-code-card{display:flex;align-items:center;gap:16px;flex-wrap:wrap;background:#0c1b24;border:1px dashed #67939e;border-radius:14px;margin-top:24px;padding:20px}.class-code-card span{display:block;color:#a2bec6;font-size:.8rem}.class-code-card strong{display:block;font:1.1rem ui-monospace,monospace;letter-spacing:.1em;margin-top:8px;overflow-wrap:anywhere}.class-code-card p{margin:0}.class-code-card button{margin-left:auto}.roster-panel .account-metrics{grid-template-columns:1fr 1fr}.roster-scroll{overflow:auto;max-width:100%;margin-top:20px}.roster-table{width:100%;border-collapse:collapse;font-size:.86rem;text-align:left}.roster-table th{color:#afcbd2;font-weight:500;white-space:nowrap}.roster-table td,.roster-table th{padding:16px 12px;border-bottom:1px solid #344e5b}.roster-table td:first-child{font-weight:600;min-width:100px;max-width:180px;overflow-wrap:anywhere}.roster-table time{font-size:.75rem;color:#a2b9c4}.roster-table meter{display:block;width:85px;height:6px;margin-top:6px}.class-empty{text-align:center;padding:36px 12px;color:#bfd4da}.class-empty>span{font-size:4rem;color:#9dcbd2}#account-feedback{min-height:24px;color:#b6e4dc}#account-sync{font-size:.9rem;color:#addbd4}#account-save-status{max-width:380px;text-align:right}
@media(max-width:1000px){.teacher-layout{grid-template-columns:1fr}.teacher-layout>aside{display:grid;grid-template-columns:1fr 1fr;gap:12px}.teacher-layout>aside>h2,.teacher-layout #account-feedback{grid-column:1/-1}.account-grid{gap:16px}.account-panel{padding:22px}.account-feature-grid{grid-template-columns:1fr}}
@media(max-width:650px){.account-grid{grid-template-columns:1fr}.account-metrics{gap:8px}.account-metrics article{padding:14px}.account-metrics strong{font-size:1.6rem}.account-metrics span{font-size:.74rem}.account-invite{padding:20px;gap:14px}.account-invite .account-orbit{display:none}.account-panel{padding:20px}.teacher-layout>aside{display:block}.teacher-heading,.class-detail-head{align-items:flex-start;flex-direction:column}.class-code-card{padding:14px}.class-code-card strong{font-size:.95rem}.class-code-card button{margin-left:0}.account-heading h1{overflow-wrap:anywhere}#account-save-status{text-align:left}.joined-class{align-items:flex-start}}

.account-panel select,.account-panel textarea{box-sizing:border-box;width:100%;font:inherit;color:#e8f3f0;background:#0a1721;border:1px solid #4b6675;border-radius:10px;padding:14px}.account-panel textarea{resize:vertical;min-height:90px}.account-panel select:focus,.account-panel textarea:focus{outline:2px solid #a5dadf;outline-offset:3px}.classroom-heading{display:flex;justify-content:space-between;align-items:center;gap:24px}.classroom-heading h1{font-size:clamp(2rem,4vw,3.2rem)}.classroom-tools{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}.classroom-tool{display:flex;align-items:center;gap:16px;text-decoration:none;color:#f1f7f6;border:1px solid #59767d;border-radius:18px;padding:22px;background:linear-gradient(130deg,#293a46,#192b36);transition:transform .18s,border-color .18s}.classroom-tool:hover{transform:translateY(-3px);border-color:#b9ebd7}.classroom-tool>span:first-child{display:grid;place-items:center;flex-shrink:0;width:46px;height:46px;border-radius:14px;font-size:1.4rem;background:#a44b553d;color:#ffb8b6}.classroom-tool.blooket>span:first-child{background:#3577a14d;color:#8edbff}.classroom-tool.kahoot>span:first-child{background:#775bac4d;color:#d8baff}.classroom-tool strong{font-size:1.15rem;display:block}.classroom-tool small{display:block;color:#b4cbd1;margin-top:5px}.classroom-tool>span:last-child{margin-left:auto;color:#afd9d3}.tools-note{font-size:.8rem;color:#9fb5c0;margin:10px 0 26px}.classroom-layout{display:grid;grid-template-columns:280px minmax(0,1fr);gap:22px;align-items:start}.classroom-sidebar{padding:22px}.classroom-sidebar details{border-top:1px solid #36505e;padding-top:18px;margin-top:20px}.classroom-sidebar summary,.room-invite summary{cursor:pointer;color:#c6e6e1;font-weight:600}.classroom-sidebar form{margin-bottom:8px}.classroom-sidebar .class-choice strong{display:block}.classroom-sidebar .class-choice small{display:block;margin-top:6px;font-size:.72rem;color:#b9cbd0}.classroom-main{padding:26px;min-height:620px}.room-header{display:flex;align-items:start;justify-content:space-between;gap:16px}.room-header h2{font-size:1.7rem;overflow-wrap:anywhere;margin:10px 0}.room-header p{font-size:.78rem;margin:0}.owner-badge{border:1px solid #77a09f;color:#c9e8d9;font-size:.7rem;border-radius:20px;padding:7px 10px;white-space:nowrap}.room-invite{margin-top:20px;background:#0c1b243d;border-radius:12px;padding:14px}.room-invite .class-code-card{margin:12px 0}.room-invite p{font-size:.8rem}.room-tabs{display:flex;gap:8px;border-bottom:1px solid #3c535f;margin:24px 0 18px;padding-bottom:12px}.room-tabs button{border:0;padding:10px 22px;border-radius:10px;background:transparent;color:#b8cbd0;font:inherit}.room-tabs button[aria-pressed=true]{background:#426771;color:#eafff8}.room-feed{max-height:470px;overflow-y:auto;overscroll-behavior:contain;padding:4px 8px 8px 0;display:flex;flex-direction:column;gap:14px;scrollbar-color:#4b717b #132632}.class-post{padding:16px;border:1px solid #3c535c;border-radius:14px;background:#132630;overflow-wrap:anywhere}.class-post.own-post{background:#213e47;border-color:#638b8c}.post-byline{display:flex;align-items:center;gap:10px;flex-wrap:wrap}.post-byline strong{font-size:.85rem}.post-byline time{font-size:.69rem;color:#9bb6c0;margin-left:auto}.member-avatar{display:grid;place-items:center;flex-shrink:0;width:32px;height:32px;border-radius:50%;background:#a5d3c4;color:#153a40;font-weight:bold}.post-hide{background:none;border:0;color:#b4c9d0;font-size:1.2rem;padding:0 8px}.class-post .post-body{white-space:pre-wrap;margin:12px 0 0;font-size:.94rem;color:#e0ecec;line-height:1.65}.class-post h3{margin:18px 0 0;font-size:1.1rem}.room-composer{border-top:1px solid #3c535f;padding-top:14px;margin-bottom:0!important}.composer-bottom{display:flex;align-items:center;justify-content:space-between;gap:16px}.composer-bottom small{color:#9fb9c3;font-size:.74rem;max-width:65%;line-height:1.6}.composer-bottom button{white-space:nowrap}.resource-intro h3{margin:8px 0}.resource-intro p{font-size:.84rem}.resource-link{display:flex;justify-content:space-between;gap:14px;background:#0c1d25;color:#bce7df;border-radius:9px;margin-top:16px;padding:13px;text-decoration:none;font-size:.82rem;overflow-wrap:anywhere}.room-member{display:flex;align-items:center;gap:14px;padding:16px 0;border-bottom:1px solid #3c535f}.room-member strong{display:block;overflow-wrap:anywhere}.room-member small{display:block;color:#a6bfc7;margin-top:5px}.room-member button{margin-left:auto}#room-progress{margin-top:26px}#room-undo{margin-top:12px;color:#bce7df;font-size:.86rem}#room-undo:empty{display:none}#classroom-feedback{font-size:.85rem;color:#bce7df;overflow-wrap:anywhere}.classroom-main button:focus-visible,.classroom-tool:focus-visible{outline:2px solid #c5efdc;outline-offset:3px}
@media(max-width:1050px){.classroom-layout{grid-template-columns:230px minmax(0,1fr)}.classroom-main{padding:20px}.classroom-tool{padding:16px;gap:10px}.classroom-tool small{font-size:.7rem}.owner-badge{display:none}}
@media(max-width:800px){.classroom-layout{grid-template-columns:1fr}.classroom-sidebar #class-list{display:flex;gap:10px;overflow-x:auto}.classroom-sidebar .class-choice{min-width:180px;max-width:260px}.classroom-main{min-height:480px}.classroom-sidebar details:not([open]){margin-top:12px;padding-top:12px}}
@media(max-width:550px){.classroom-heading{align-items:start;flex-direction:column;gap:10px}.classroom-tools{gap:8px}.classroom-tool{display:block;text-align:center;padding:14px 6px}.classroom-tool>span:first-child{margin:0 auto 10px;width:36px;height:36px}.classroom-tool>span:last-child{display:none}.classroom-tool strong{font-size:.95rem}.classroom-tool small{font-size:.65rem}.classroom-main{padding:16px}.room-header{flex-wrap:wrap}.room-tabs button{padding:10px 18px}.composer-bottom{align-items:start;flex-direction:column}.composer-bottom small{max-width:none}.composer-bottom button{width:100%}.post-byline time{font-size:.64rem}.resource-link{flex-direction:column}.classroom-heading h1{font-size:2.2rem}}
@media(prefers-reduced-motion:reduce){.classroom-tool{transition:none}.classroom-tool:hover{transform:none}}
.startup-screen{max-width:720px;min-height:100vh;display:flex;flex-direction:column;justify-content:center;gap:22px;padding:40px;font-family:system-ui,sans-serif}.startup-screen h1{font-family:system-ui,sans-serif}.startup-screen [hidden]{display:none}.startup-screen #startup-status{font-size:14px;color:#b9d9e9}.startup-screen .quiet{align-self:flex-start}
.account-required .canopy,.account-required .topbar nav,.account-required .environment-controls,.account-required footer,.account-required .header-channel{display:none!important}.account-required .flight-deck{max-width:1190px}.account-required .topbar{padding:20px 28px}.account-required main{padding-top:32px}.account-required .account-heading{max-width:720px}.account-required .account-heading .lead{max-width:620px}

/* insights.css */
.statistics-toolbar{display:flex;justify-content:space-between;align-items:center;gap:18px;margin-bottom:24px}.statistics-toolbar p{font-size:.83rem}.statistics-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}.stat-tile{padding:26px;border:1px solid #3e5c68;border-radius:18px;background:linear-gradient(145deg,#28464d,#142531)}.stat-tile strong{display:block;color:#c4efdf;font-size:3rem;letter-spacing:-2px}.stat-tile h2{overflow-wrap:anywhere;font-size:1rem;margin:14px 0 8px;letter-spacing:0}.stat-tile p{font-size:.8rem;line-height:1.6}.statistics-panels{display:grid;grid-template-columns:1.2fr 1fr;gap:22px;margin:24px 0}.signup-chart{display:flex;gap:16px;align-items:end;justify-content:space-between;height:195px;margin:24px 0}.signup-chart>div{flex:1;display:flex;align-items:center;flex-direction:column;gap:10px;min-width:0}.signup-chart i{display:block;background:linear-gradient(#abdccb,#4a929d);width:100%;max-width:52px;border-radius:7px 7px 2px 2px}.signup-chart small{font-size:.7rem;color:#aec8cf}.signup-chart strong{color:#daf5e9;font-size:.8rem}.stat-breakdown{margin:20px 0}.stat-breakdown>div{display:flex;justify-content:space-between;padding:14px 0;border-bottom:1px solid #3a5662}.stat-breakdown dd{font-weight:700;color:#c5ecdc}.stat-breakdown dt{color:#bacdd3}.offline-layout{display:grid;grid-template-columns:1.15fr 1fr;gap:24px}.offline-emblem{display:grid;place-items:center;width:70px;height:70px;font-size:2.6rem;background:#355d63;border-radius:20px;color:#c6ead9;margin-bottom:28px}.offline-pack p{margin:18px 0}.offline-pack .account-actions{margin:24px 0}.offline-pack progress{width:100%;accent-color:#a4dfc8;height:14px}.offline-list{padding-left:22px;color:#bed0d5;line-height:1.8;margin:20px 0 28px}.offline-layout aside p{margin:16px 0}.offline-layout aside .quiet{display:inline-block;margin-top:18px}#connection-notice{position:sticky;top:0;z-index:30;background:#294b55;border-bottom:1px solid #78a9aa;color:#e0f1e9;text-align:center;padding:11px 20px;font-size:.82rem}#connection-notice[hidden]{display:none}.utility-links{display:flex;gap:18px;flex-wrap:wrap;font-size:.85rem;color:#b5d8db;margin-top:12px}.offline-shortcut{display:inline-flex;align-items:center;gap:10px;border:1px solid #537981;background:#142e3a;padding:12px 16px;border-radius:10px;margin:24px 0 0;color:#c3e6dc}
@media(max-width:750px){.statistics-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.statistics-panels,.offline-layout{grid-template-columns:1fr}.stat-tile{padding:20px}.stat-tile strong{font-size:2.5rem}.statistics-toolbar{align-items:start;flex-direction:column}.signup-chart{gap:10px}}
@media(max-width:480px){.statistics-grid{grid-template-columns:1fr}.offline-pack .account-actions button{width:100%}}

/* research.css */
.research-heading{margin:28px 0}.research-heading h1{max-width:880px}.research-heading p{margin-top:16px;max-width:800px}.research-nav{display:flex;flex-wrap:wrap;gap:10px;margin-bottom:25px}.research-nav a{padding:10px 16px;border:1px solid #3c5d6b;border-radius:24px;background:#132632;font-size:14px}.research-invite{display:block;margin:28px 0;padding:30px;border:1px solid #58887f;border-radius:18px;background:radial-gradient(ellipse at top right,#254a4b,transparent 60%),#122831}.research-invite h2{font-size:30px}.research-invite p{margin:12px 0 20px}.research-storage{border-left:3px solid #88c6bb;padding:10px 18px;margin:20px 0;font-size:14px}.research-topic-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(min(100%,240px),1fr));gap:18px;margin:24px 0}.research-topic{display:flex;flex-direction:column;padding:25px;border:1px solid #355462;background:#142935;border-radius:15px;transition:transform .2s,border-color .2s}.research-topic:hover{transform:translateY(-3px);border-color:#9bdbcc}.research-topic p{margin:14px 0 22px;font-size:15px}.research-topic>span:last-child{margin-top:auto;color:#a2dfd2;font-size:14px}.research-metrics{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:14px;margin:22px 0}.research-metrics article{display:grid;gap:9px;padding:20px;background:#172d37;border:1px solid #36565e;border-radius:12px}.research-metrics strong{font:600 32px 'Space Grotesk',sans-serif;color:#b5eadb}.research-metrics small{color:#a4bfc4}.research-panel,.research-check{padding:26px;margin-bottom:20px;background:#11232e;border:1px solid #34515e;border-radius:16px;min-width:0}.research-panel h2,.research-check h2{margin-bottom:16px}.research-panel h3{margin:18px 0 10px}.research-panel p+.research-source,.research-panel p+p{margin-top:14px}.research-panel ul,.research-panel ol{padding-left:24px;line-height:1.9;color:#bed0d5}.research-panel li+li{margin-top:14px}.research-panel summary{cursor:pointer;color:#b4e4dc;font-weight:600}.research-work-grid{display:grid;grid-template-columns:minmax(0,2fr) minmax(230px,1fr);gap:24px;align-items:start}.research-work-grid>div,.research-work-grid>aside{min-width:0}.research-work-actions{display:flex;gap:10px;flex-wrap:wrap;margin:20px 0}.research-work-grid label,.research-panel form>label{display:block;margin:18px 0 8px;color:#d5e7e8;font-size:14px;line-height:1.6}.research-panel input:not([type=radio]),.research-panel textarea,.research-panel select,.research-check select{display:block;width:100%;padding:12px;background:#091922;color:#ecf6f6;border:1px solid #466572;border-radius:8px;font:inherit;margin:7px 0}.research-panel textarea{resize:vertical;min-height:90px}.research-panel [readonly]{color:#a9bdc6;background:#10212a}.research-panel button{margin-top:12px}.research-controls{display:grid;grid-template-columns:1fr 1fr;gap:18px}.research-result{font:600 29px 'Space Grotesk',sans-serif;color:#a2e6d4;margin:15px 0}.research-question{border:0;border-bottom:1px solid #35505b;margin:20px 0;padding:0 0 20px}.research-question legend{font-size:16px;color:#e1eded;line-height:1.6;margin-bottom:8px}.research-question label{display:flex;gap:12px;align-items:center;padding:10px;background:#172e3a;border-radius:8px;margin:7px 0}.research-question input{accent-color:#a0dece;width:18px;height:18px;flex:none}.research-check form>fieldset{border:0;margin:0;padding:0}.research-check fieldset:disabled{opacity:.55}.research-table-scroll{overflow:auto;max-width:100%;margin:20px 0}.research-table-scroll table{width:100%;border-collapse:collapse;font-size:14px}.research-table-scroll caption{text-align:left;padding:10px 0;color:#b5ddda;font-weight:600}.research-table-scroll th,.research-table-scroll td{text-align:left;padding:12px;border-bottom:1px solid #34515e;line-height:1.6}.research-chart{width:100%;height:auto;margin-top:20px;color:#6f929b}.research-chart text{fill:#b5cbd1;font:13px sans-serif}.research-comparison{padding:18px;background:#1b343d;border-radius:12px}.research-model-note{margin:24px 0;padding:18px;border:1px solid #476678;border-radius:10px}.research-model-note summary{cursor:pointer;color:#b3dcd6;font-weight:600}.research-model-note p{margin:12px 0;font-size:14px}.research-model-note h3{font-size:16px;margin:15px 0}.research-model-note>a{margin-top:14px}.research-source{display:block;color:#a7e7da;font-size:14px;margin:14px 0;text-decoration:underline;text-underline-offset:4px}.research-entry{display:flex;justify-content:space-between;align-items:center;gap:20px;padding:18px 2px;border-bottom:1px solid #35515f}.research-entry small{display:block;color:#9db9c2;margin-top:8px}.research-section-head{display:flex;align-items:center;justify-content:space-between;gap:12px;flex-wrap:wrap}.research-status{position:sticky;bottom:10px;z-index:3;background:#213c43;border-radius:10px;box-shadow:0 8px 30px #0005;padding:12px 18px;color:#d3f6e8;white-space:pre-wrap}.research-status:empty{display:none}#assignment-text{white-space:pre-wrap;overflow-wrap:anywhere;font:inherit;font-size:14px;line-height:1.8;padding:16px;border:1px solid #45646c;border-radius:10px;margin:15px 0}#assignment-rooms{margin-top:22px}#research-visual .activity-diagram{width:100%;height:auto}.research-panel input[aria-invalid=true]{border-color:#f8a5a5}@media(max-width:800px){.research-work-grid{grid-template-columns:1fr}.research-work-grid>aside{display:grid;gap:15px;grid-template-columns:repeat(auto-fit,minmax(230px,1fr))}.research-panel,.research-check{padding:20px}.research-invite{padding:23px}.research-heading h1{font-size:34px}}@media(max-width:420px){.research-controls{grid-template-columns:1fr;gap:0}.research-metrics{grid-template-columns:1fr 1fr}.research-nav a{padding:8px 12px;font-size:12px}.research-panel,.research-check{padding:16px}.research-table-scroll table{font-size:12px}}@media(prefers-reduced-motion:reduce){.research-topic{transition:none}}

/* immersive.css */
/* Original observatory / flight-deck art, with no video or third-party runtime. */
body{background:radial-gradient(ellipse at 82% 0,#162b4866,transparent 55%),#060d18}
.topbar{flex-wrap:wrap;gap:15px}.topbar nav{flex:1;display:flex;flex-wrap:wrap}.topbar nav a{padding:10px 12px;flex:1;white-space:nowrap}.header-channel{display:none}
.environment-controls{display:flex;align-items:center;flex-wrap:wrap;gap:5px;margin:12px 8px 0;padding:8px 12px;border-bottom:1px solid #34495c;color:#99b4c9;font-size:11px;letter-spacing:1px}.environment-label{margin-right:auto}.environment-controls button{color:#abc2d4;background:transparent;border:1px solid transparent;border-radius:20px;padding:7px 13px;font:inherit;cursor:pointer;min-height:34px}.environment-controls button[aria-pressed=true]{border-color:#7fb9ca;background:#234253;color:#e0f5f8}.environment-controls button:hover{color:white;border-color:#4e7187}#ambient-motion{margin-left:8px;border-left:1px solid #385063;border-radius:0;font-size:10px}
.canopy{background:#07111f;isolation:isolate}.canopy>.observatory-scene{position:absolute;inset:-40% 0;width:100%;height:180%;z-index:-1;opacity:.8}.canopy::before{content:"";position:absolute;inset:0;background:linear-gradient(90deg,#05101dba,transparent 80%);z-index:0}.canopy-copy p{max-width:580px}.space-scene,.cockpit-scene{transition:opacity .8s ease;pointer-events:none}.cockpit-scene{opacity:0}[data-environment=cockpit] .space-scene{opacity:0}[data-environment=cockpit] .cockpit-scene{opacity:1}
.research-hero{position:relative;isolation:isolate;min-height:570px;overflow:hidden;border:1px solid #446179;border-radius:26px;background:#040c19;margin:24px 0 32px;box-shadow:0 25px 80px #0004}.research-hero>.observatory-scene{position:absolute;inset:-2%;height:104%;width:104%;z-index:-2;transform:translate3d(var(--look-x,0),var(--look-y,0),0);transition:transform .8s cubic-bezier(.16,1,.3,1)}.hero-shade{position:absolute;inset:0;z-index:-1;background:linear-gradient(90deg,#040c19ef 5%,#040c19a8 37%,#040c1900 78%),linear-gradient(0deg,#040c19f0,transparent 35%)}.research-hero-copy{padding:54px 52px 110px;max-width:650px}.research-hero h1{font-size:clamp(48px,6.5vw,83px);font-weight:400;line-height:.98;letter-spacing:-4px;margin:26px 0}.research-hero h1 em{font-style:normal;color:#a6e2ed}.research-hero-copy p{font-size:16px;line-height:1.8;color:#abc0d3;margin:20px 0 28px}.research-hero-copy .primary{gap:25px;border-radius:30px;min-height:50px;padding:13px 24px}.research-hero-copy .kicker{display:flex;align-items:center;gap:10px;font-size:9px;letter-spacing:2px}.signal-dot{display:inline-block;width:5px;height:5px;background:#a1e9d4;border-radius:50%;box-shadow:0 0 12px #7ef6d7}
.hero-coordinate{position:absolute;right:32px;top:40px;display:flex;flex-direction:column;gap:7px;color:#b5d6e3;font:8px monospace;letter-spacing:2px;text-align:right}.hero-bottom{position:absolute;bottom:0;left:0;right:0;padding:22px 34px;border-top:1px solid #89bbd333;display:flex;align-items:center;gap:20px;background:#06122155;font-size:9px;letter-spacing:2px;color:#b7cfde;backdrop-filter:blur(8px)}.hero-bottom b{font-weight:400;color:#496e80}.hero-bottom small{margin-left:auto;max-width:225px;letter-spacing:.2px;line-height:1.6;font-size:10px;color:#8ca7b9}
.research-nav{margin-bottom:0}.research-nav a{background:transparent;border-color:#344b60;color:#b8cfdd;transition:background .25s,border-color .25s}.research-nav a:hover{background:#1a3448;border-color:#8dbdce}
[data-page=research] .research-panel,[data-page=research] .research-check{background:linear-gradient(135deg,#13263aea,#0c1a2ae8);border-color:#314b61;box-shadow:inset 0 1px #a5d9e509,0 12px 35px #0002}.research-topic{position:relative;overflow:hidden;padding:22px;background:linear-gradient(155deg,#192d43,#0b1829);border-color:#35516b;transition:transform .5s cubic-bezier(.16,1,.3,1),border-color .4s,box-shadow .4s}.research-topic:hover{transform:translateY(-7px);border-color:#91c7d8;box-shadow:0 18px 40px #0004}.research-topic h2{font-size:26px;letter-spacing:-.7px}.research-topic p{font-size:14px;line-height:1.8}.topic-art{width:100%;height:150px;fill:none;stroke:#87b5c9;stroke-width:1.5;margin:5px 0 12px;transition:transform .7s}.topic-art .art-orbit{stroke:#456480;stroke-dasharray:2 9;opacity:.6}.topic-art .art-solid{fill:#addfec;stroke:none}.topic-art .art-accent{stroke:#b7f4e1;stroke-width:3}.research-topic:hover .topic-art{transform:scale(1.06) rotate(-3deg)}
.research-metrics article{background:#101f30;border-color:#2e465d;border-radius:12px}.research-metrics strong{color:#b9e3ed}.research-storage{color:#94adbf;border-color:#426880;background:#0c182750;font-size:12px;line-height:1.8}.research-work-actions{gap:8px}.research-simulation{padding:16px;margin:22px -5px 0;border:1px solid #456277;border-radius:18px;background:radial-gradient(ellipse at 70% 20%,#23486555,transparent 70%),#071421;box-shadow:inset 0 2px 20px #0005}.research-simulation .subtle{font-size:12px}.research-simulation #research-visual{border:1px solid #4d728740;border-radius:12px;overflow:hidden;background:linear-gradient(#102c3d44,#102c3d00),repeating-linear-gradient(90deg,transparent,transparent 39px,#6facbc0b 40px)}.experiment-transport{display:flex;flex-wrap:wrap;align-items:center;gap:10px;border-bottom:1px solid #385669;margin-bottom:18px;padding:10px 0 18px}.experiment-transport label{font-size:11px!important;margin:8px 0!important;width:100%}.experiment-transport input[type=range]{appearance:auto;accent-color:#a5dedb;padding:0;background:transparent;height:20px;margin:0;flex:1;min-width:120px;border:0}.experiment-transport output{color:#b3e6e8;font:11px monospace;min-width:170px}.experiment-transport button{font-size:12px;margin:0}.research-result{font-variant-numeric:tabular-nums}
.planet-system{transform-origin:1020px 340px;animation:planet-hover 18s ease-in-out infinite alternate}.star-drift{animation:star-drift 35s ease-in-out infinite alternate}.cloud-drift{animation:cloud-drift 30s ease-in-out infinite alternate}.orbiter{animation:orbiter-drift 12s ease-in-out infinite alternate}
@keyframes planet-hover{to{transform:translate(-8px,-12px) rotate(2deg)}}@keyframes star-drift{to{transform:translate(18px,-8px)}}@keyframes cloud-drift{to{transform:translateX(-35px)}}@keyframes orbiter-drift{to{transform:translate(20px,-10px)}}
[data-ambient-motion=paused] .observatory-scene *,[data-ambient-hidden=true] .observatory-scene *{animation-play-state:paused!important}[data-ambient-motion=paused] .research-hero>.observatory-scene{transform:none;transition:none}
@media(max-width:1100px){.topbar nav a{font-size:12px;padding:10px}.research-hero-copy{padding:48px 38px 110px}.hero-coordinate{font-size:7px}.research-hero{min-height:540px}}
@media(max-width:760px){.topbar nav{display:flex;flex-wrap:nowrap;overflow-x:auto;justify-content:flex-start;width:100%;scrollbar-width:thin}.topbar nav a{flex:none;min-width:85px}.research-hero{min-height:530px;border-radius:18px}.research-hero>.observatory-scene{width:170%;left:-55%;opacity:.85}.hero-shade{background:linear-gradient(90deg,#040c19eb,#040c1960),linear-gradient(0deg,#040c19,transparent 65%)}.research-hero-copy{padding:50px 28px 110px;max-width:440px}.research-hero h1{font-size:61px;letter-spacing:-3px}.hero-coordinate{display:none}.hero-bottom{padding:18px 24px;gap:12px;flex-wrap:wrap}.hero-bottom small{max-width:none;width:100%;margin:0;font-size:9px}.research-topic-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.topic-art{height:125px}.research-topic{padding:18px}.research-topic h2{font-size:23px}.environment-controls{padding:8px 3px;font-size:10px}.environment-label{display:none}.environment-controls button{padding:7px 10px}.research-hero-copy .kicker{font-size:8px}}
@media(max-width:440px){.research-topic-grid{grid-template-columns:1fr}.research-topic{display:grid;grid-template-columns:1fr 105px;column-gap:12px}.research-topic .kicker{grid-column:1/-1;font-size:8px}.research-topic .topic-art{grid-column:2;grid-row:2/5;align-self:center;width:110px;height:130px}.research-topic h2,.research-topic p,.research-topic>span:last-child{grid-column:1}.research-topic p{font-size:12px;margin:10px 0 15px}.research-topic>span:last-child{font-size:11px}.research-hero h1{font-size:52px}.research-hero-copy{padding:42px 23px 120px}.research-hero-copy p{font-size:14px}.research-hero-copy .primary{font-size:12px;gap:10px}.research-hero{min-height:525px}.experiment-transport output{min-width:100%;font-size:12px}}
@media(prefers-reduced-motion:reduce){.observatory-scene *{animation:none!important}.research-hero>.observatory-scene,.research-topic:hover,.research-topic:hover .topic-art{transform:none;transition:none}}

.research-hero-copy>*{animation:observatory-arrival .8s cubic-bezier(.16,1,.3,1) both}.research-hero-copy h1{animation-delay:70ms}.research-hero-copy p{animation-delay:140ms}.research-hero-copy>a{animation-delay:210ms}@keyframes observatory-arrival{from{opacity:0;transform:translateY(18px)}to{opacity:1;transform:none}}

/* phet.css */
.phet-hero{display:grid;grid-template-columns:1.5fr 1fr;gap:30px;align-items:center;padding:46px;border:1px solid #3a6176;border-radius:24px;background:radial-gradient(ellipse at 100% 10%,#28566388,transparent 65%),#101f30;margin-bottom:38px;overflow:hidden}.phet-hero h1{font-size:clamp(38px,5vw,65px);line-height:1.07;font-weight:500;margin:20px 0;letter-spacing:-2px}.phet-hero em{font-style:normal;color:#b4ead9}.phet-hero p{max-width:490px;line-height:1.8;color:#b5c9d4;font-size:15px}.phet-hero-tags{display:flex;flex-wrap:wrap;gap:16px;margin-top:26px;color:#99c5cf;font-size:11px}.phet-hero-tags span+span{border-left:1px solid #52707b;padding-left:16px}.phet-hero-art{text-align:center;color:#94c9d4;font:9px monospace;letter-spacing:2px}.phet-hero-art svg{width:100%;max-height:250px}.phet-card-art svg,.phet-hero-art svg,.phet-launch svg{fill:none;stroke:#bce9e4;stroke-width:2;stroke-linecap:round;stroke-linejoin:round}.phet-orbit{stroke:#5d8794;stroke-dasharray:2 10;opacity:.45}.phet-library-header{display:flex;justify-content:space-between;gap:25px;align-items:end;margin-bottom:24px}.phet-library-header h2{font-size:26px}.phet-library-header p{margin-top:10px;color:#9fb7c8;font-size:14px}.phet-search{display:grid;gap:8px;min-width:260px;font-size:12px;color:#b1c8d6}.phet-search input{width:100%;background:#0b1927;color:#eaf7fa;border:1px solid #48677e;border-radius:12px;padding:13px 16px;font:inherit;min-height:46px}.phet-filters{display:flex;flex-wrap:wrap;gap:8px;margin:12px 0 18px}.phet-filters button{cursor:pointer;min-height:40px;padding:9px 18px;border:1px solid #3b566b;border-radius:24px;color:#b7ccda;background:#101f30;font:inherit;font-size:12px}.phet-filters button[aria-pressed=true]{background:#bce7da;color:#092733;border-color:#d0f6e9}.phet-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:20px;margin:18px 0 32px}.phet-card{display:flex;flex-direction:column;border:1px solid #34536a;border-radius:18px;overflow:hidden;background:#101e2f;transition:transform .25s,border-color .25s}.phet-card:hover{transform:translateY(-4px);border-color:#a5d7d6}.phet-card-art{position:relative;height:175px;background:radial-gradient(ellipse at center,#244d5a99,#0f2032)}.phet-card-art svg{width:100%;height:100%}.phet-card-art .tag{position:absolute;top:15px;left:15px;background:#101d2be6;font-size:9px}.phet-card-copy{padding:23px;display:flex;flex:1;flex-direction:column}.phet-card-copy small{color:#a1d7c9;font-size:10px;letter-spacing:1px}.phet-card h2{font-size:21px;line-height:1.3;margin:12px 0}.phet-card p{font-size:13px;line-height:1.8;color:#a7bfce;margin-bottom:22px}.phet-card-action{display:flex;justify-content:space-between;gap:12px;font-size:12px;color:#bbe9df;margin-top:auto}.phet-card-action b{font-weight:normal}.phet-credit{font-size:11px!important;line-height:1.8!important;color:#9db3c5!important}.phet-credit a,.phet-footnote a,.phet-followup a:not(.quiet){text-decoration:underline;text-underline-offset:3px;color:#b4dcd9}.phet-footnote{padding:22px;border:1px solid #314b62;border-radius:14px;color:#a9bfce;font-size:12px;line-height:1.8}.phet-footnote>p:first-child{margin-bottom:10px}.phet-detail-heading{display:flex;align-items:start;justify-content:space-between;gap:24px;margin:28px 0}.phet-detail-heading h1{font-size:clamp(28px,4vw,44px);margin:15px 0}.phet-detail-heading p{color:#afc5d3;line-height:1.8}.phet-detail-heading>.tag{white-space:nowrap}.phet-question{padding:20px 24px;border-left:3px solid #b6dfcf;background:#152c36;margin:20px 0;border-radius:0 12px 12px 0}.phet-question p{line-height:1.7;margin-top:10px;color:#d0e6e8}.phet-player{background:#071421;border:1px solid #4d6b80;border-radius:17px;overflow:hidden}.phet-player-toolbar{padding:16px 20px;display:flex;align-items:center;justify-content:space-between;gap:15px;font-size:12px;color:#a5c4d4;background:#142a39}.phet-player-toolbar>div{display:flex;align-items:center;flex-wrap:wrap;gap:14px}.phet-player-toolbar a{color:#c3ede2;text-decoration:underline;text-underline-offset:3px}.phet-player-toolbar .quiet{font-size:12px}.phet-stage{aspect-ratio:834/504;background:#091420;display:grid;place-items:center}.phet-stage iframe{width:100%;height:100%;border:0;background:white}.phet-launch{text-align:center;max-width:500px;padding:28px}.phet-launch svg{width:145px;height:90px}.phet-launch h2{font-size:26px;margin:14px 0}.phet-launch p{font-size:13px;line-height:1.7;color:#acc4d4;margin:15px 0}.phet-launch .subtle{font-size:11px}.phet-player .phet-credit{margin:0;padding:12px 20px}.phet-player #phet-status:not(:empty){padding:12px 20px;font-size:12px;line-height:1.7;background:#193342;color:#c8e6e9}.phet-followup{display:grid;grid-template-columns:1fr 1fr;gap:24px;margin-top:25px}.phet-followup section{padding:26px;border:1px solid #355166;border-radius:15px;background:#112332}.phet-followup h2{font-size:20px;margin-bottom:15px}.phet-followup p{font-size:13px;line-height:1.8;color:#adc4d2;margin-bottom:18px}.phet-followup .subtle{font-size:11px;margin-top:16px}.phet-empty{grid-column:1/-1;padding:45px;text-align:center;border:1px dashed #4a6579;border-radius:18px}.phet-empty p{margin:15px 0}.phet-player:fullscreen{display:flex;flex-direction:column;background:#071421;border-radius:0;overflow:auto}.phet-player:fullscreen .phet-stage{flex:1;aspect-ratio:auto;min-height:0}.phet-player:fullscreen iframe{min-height:250px}
/* Keep all main sections visible and keyboard accessible as the library grows. */
.topbar{display:grid;grid-template-columns:1fr auto;padding:18px 22px}.topbar .brand{grid-column:1;grid-row:1;justify-self:start}.topbar .language-picker{grid-column:2;grid-row:1}.topbar>nav{grid-column:1/-1;grid-row:2;display:grid;width:100%;grid-template-columns:repeat(8,minmax(0,1fr));gap:5px;min-width:0}.topbar nav a{min-width:0;font-size:12px;padding:10px 6px;white-space:normal;line-height:1.4;text-align:center}.topbar .nav-number{display:none}.topbar nav a[aria-current=page]{box-shadow:inset 0 -2px #a6e6d9;background:#244955}.topbar nav a:focus-visible{outline-offset:-3px}textarea:focus-visible{outline:2px solid #c4eade;outline-offset:4px}
@media(max-width:850px){.phet-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.phet-hero{padding:30px;grid-template-columns:1.6fr 1fr}.phet-hero-art{font-size:7px}.phet-library-header{align-items:start;flex-direction:column}.phet-search{width:100%}.phet-detail-heading{display:block}.phet-detail-heading>.tag{display:inline-block;margin-top:16px}.phet-followup{gap:15px}.phet-player-toolbar{align-items:start;flex-direction:column}}
@media(max-width:600px){.topbar>nav{grid-template-columns:repeat(4,minmax(0,1fr));overflow:visible}.topbar nav a{font-size:11px;min-height:44px}.phet-hero{padding:27px;grid-template-columns:1fr}.phet-hero-art{display:none}.phet-grid{grid-template-columns:1fr}.phet-card{display:grid;grid-template-columns:105px 1fr}.phet-card-art{height:100%;min-height:190px}.phet-card-art .tag{left:9px;top:12px;font-size:7px;padding:5px}.phet-card-copy{padding:20px}.phet-card h2{font-size:20px}.phet-followup{grid-template-columns:1fr}.phet-stage{aspect-ratio:834/620}.phet-stage:has(.phet-launch){min-height:330px;aspect-ratio:auto}.phet-launch{padding:22px}.phet-hero h1{font-size:39px}.phet-player-toolbar{padding:14px}.phet-detail-heading h1{font-size:32px}}
@media(prefers-reduced-motion:reduce){.phet-card{transition:none}.phet-card:hover{transform:none}}

/* cyber.css */
/* Theme only: retain feature layouts, simulation graphics, and semantic states. */
:root {
  --display: 'Chakra Petch', 'Space Grotesk', system-ui, sans-serif;
  --mono: 'Share Tech Mono', ui-monospace, SFMono-Regular, Consolas, monospace;
  --body: 'IBM Plex Sans', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --bg: #07111f;
  --panel: #0b1f33;
  --line: #284860;
  --muted: #adc1d2;
  --text: #e6f1f8;
  --cyan: #22d3ee;
  --cyber-cyan-deep: #06b6d4;
  --cyber-panel-edge: #356179;
  --cyber-focus: #9bf3ff;
  color-scheme: dark;
  font-family: var(--body);
}
body {
  background-color: var(--bg);
  background-image: radial-gradient(ellipse at 90% 0, #123b5752, transparent 55%),
    linear-gradient(#22d3ee06 1px, transparent 1px),
    linear-gradient(90deg, #22d3ee06 1px, transparent 1px);
  background-size: auto, 48px 48px, 48px 48px;
  color: var(--text);
  font-family: var(--body);
}
h1, h2, h3, h4, .brand, .canopy-copy p { font-family: var(--display); }
h1, h2 { letter-spacing: -.025em; }
.brand { font-weight: 700; letter-spacing: -.02em; }
.kicker { color: #77e5f5; font-family: var(--mono); letter-spacing: .13em; }
.subtle { color: var(--muted); }
.topbar {
  background: linear-gradient(135deg, #102a40f5, #091a2bf5);
  border-color: #31556e;
  border-top-color: #48768a;
  border-radius: 0 0 4px 4px;
  box-shadow: 0 14px 35px #02081266;
}
.topbar nav { background: #061321b8; border-color: #25475e; border-radius: 4px; }
.topbar nav a { border-radius: 3px; color: #b1c7d7; min-height: 44px; }
.topbar nav a:hover { background: #12364c; color: #e6faff; }
.topbar nav a[aria-current] {
  background: linear-gradient(135deg, #12475e, #0b2c42);
  border-color: #22d3ee9c;
  color: #c6f9ff;
  box-shadow: inset 0 1px 0 #78efff25, 0 0 16px #22d3ee0d;
}
.topbar nav a[aria-current]::after { background: var(--cyan); box-shadow: 0 0 9px #22d3ee80; }
.topbar nav a[aria-current] .nav-number { color: #78e9fa; }
.nav-number { font-family: var(--mono); }
.environment-controls { border-color: #2b4b60; }

/* Corner marks use backgrounds, leaving contextual card pseudo-elements alone. */
.account-panel, .research-panel, .stat-tile, .offline-pack,
.knowledge-check, .activity, .next-card, .progress-levels section {
  border-color: var(--cyber-panel-edge);
  border-radius: 4px;
  background-color: var(--panel);
  background-image: linear-gradient(#22d3eead, #22d3eead),
    linear-gradient(#22d3eead, #22d3eead), linear-gradient(#22d3ee70, #22d3ee70),
    linear-gradient(#22d3ee70, #22d3ee70), linear-gradient(135deg, #102b40, #0a1b2c);
  background-position: left top, left top, right bottom, right bottom, 0 0;
  background-size: 18px 2px, 2px 18px, 18px 2px, 2px 18px, 100% 100%;
  background-repeat: no-repeat;
  box-shadow: 0 12px 30px #02091224;
}
.current-card, .research-hero, .physics-invite, .research-invite,
.physics-topic-card, .research-topic, .level-row, .video-card {
  border-radius: 4px;
  border-color: #31556d;
}
.level-row.current { border-color: #22d3ee8c; background: linear-gradient(120deg, #103449, #0d2235); }
.level-number { font-family: var(--display); }
.level-row.current .level-number { border-color: #48c5d9; color: #a4f3ff; }
.room-tabs button[aria-pressed=true], .class-choice[aria-pressed=true] {
  background: #12394b;
  border-color: #43bfd4;
  color: #d3faff;
}
button, .primary, .quiet { min-height: 44px; }
.experiment-actions .quiet, .lab-playback button, .environment-controls button,
.room-tabs button, .language-picker button { min-height: 44px; }
.primary {
  border: 1px solid #64e7f8;
  border-radius: 4px;
  background-color: var(--cyan);
  background-image: linear-gradient(110deg, transparent 35%, #ffffff42 48%, transparent 62%),
    linear-gradient(135deg, #22d3ee, #06b6d4);
  background-size: 240% 100%, 100% 100%;
  background-position: 130% 0, 0 0;
  color: #062334;
  font-family: var(--display);
  font-weight: 700;
  line-height: 1.35;
  box-shadow: inset 0 1px 0 #ffffff55, 0 5px 16px #020b174d;
  transition: transform .18s ease, box-shadow .2s ease, background-position .45s ease;
}
.primary:hover:not(:disabled):not([aria-disabled=true]) {
  background-color: #48dff2;
  background-image: linear-gradient(110deg, transparent 35%, #ffffff42 48%, transparent 62%),
    linear-gradient(135deg, #57e5f6, #16c4df);
  background-size: 240% 100%, 100% 100%;
  background-position: -30% 0, 0 0;
  color: #062334;
  box-shadow: inset 0 1px 0 #ffffff66, 0 8px 24px #22d3ee25;
  transform: translateY(-2px);
}
.primary:active:not(:disabled):not([aria-disabled=true]) { transform: translateY(0); }
.quiet {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  background: linear-gradient(135deg, #123249, #0d2539);
  border: 1px solid #416c83;
  border-radius: 4px;
  color: #c0e9f5;
  line-height: 1.4;
  transition: border-color .18s ease, background .18s ease, color .18s ease;
}
.quiet:hover:not(:disabled):not([aria-disabled=true]) {
  border-color: #58d5e8;
  background: #174258;
  color: #effdff;
}
/* No generic button colour reset: danger, grading, and moderation keep their meaning. */
:where(a, button, input, select, textarea, summary):focus-visible {
  outline: 2px solid var(--cyber-focus);
  outline-offset: 4px;
}
.classroom-main button:focus-visible, .classroom-tool:focus-visible,
.account-panel input:focus-visible, .account-panel select:focus-visible,
.account-panel textarea:focus-visible { outline: 2px solid var(--cyber-focus); outline-offset: 4px; }
input, select, textarea { accent-color: var(--cyan); }
@media (max-width: 760px) {
  .topbar nav a { padding-inline: 10px; }
  .primary, .quiet { max-width: 100%; }
  .primary { padding-inline: 18px; }
  .environment-controls button { padding-inline: 9px; }
}
@media (prefers-reduced-motion: reduce) {
  .primary, .quiet, .topbar nav a { transition: none; }
  .primary:hover:not(:disabled):not([aria-disabled=true]),
  .primary:active:not(:disabled):not([aria-disabled=true]) { transform: none; }
}

/* cyber-auth.css */
/* The account screen borrows the reference's blueprint and instrument-panel language. */
.account-required{background-color:#06101d;background-image:radial-gradient(ellipse at 12% 32%,#0d526e35,transparent 52%),radial-gradient(ellipse at 95% 10%,#65296318,transparent 40%),linear-gradient(#1b587015 1px,transparent 1px),linear-gradient(90deg,#1b587015 1px,transparent 1px);background-size:auto,auto,48px 48px,48px 48px}
.account-required::before,.account-required::after{display:none}.account-required .flight-deck{max-width:1320px;padding:0 30px;margin-top:0}.account-required .topbar{background:transparent;border:0;border-bottom:1px solid #18374b;border-radius:0;box-shadow:none;padding:24px 0}.account-required main{max-width:1320px;padding:54px 30px 70px}.account-required .brand{font-family:var(--display);letter-spacing:0;font-size:27px}.account-required .language-picker select{border-radius:5px;background:#0b1a2a}
.signup-layout{display:grid;grid-template-columns:minmax(0,1.12fr) minmax(360px,.88fr);gap:clamp(35px,6vw,90px);align-items:start}.signup-story{padding:18px 0}.signup-story .kicker{display:flex;align-items:center;gap:10px;letter-spacing:2.1px;font-size:10px;color:#79cadc}.signup-dot{width:6px;height:6px;border-radius:50%;background:#31d7ec;box-shadow:0 0 12px #21b8d7}.signup-story h1{font-family:var(--display);font-size:clamp(40px,4.7vw,64px);letter-spacing:-2px;line-height:1.05;margin:22px 0}.signup-story h1 span{color:#45deef}.signup-intro{max-width:450px;font-size:16px;line-height:1.8;color:#a6bdce}.signup-blueprint{margin:22px -10px 20px;position:relative;max-width:560px}.signup-blueprint svg{width:100%;display:block;max-height:310px}.blueprint-caption{display:flex;justify-content:space-between;margin:0 35px;font:9px var(--mono);letter-spacing:1.6px;color:#70a0b6}.signup-aircraft{transform-origin:center;transition:transform .5s ease}.signup-blueprint:hover .signup-aircraft{transform:translateY(-5px)}
.signup-perks{margin:28px 0 0;padding:0;list-style:none;display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px}.signup-perks li{border-top:1px solid #244258;padding-top:14px}.signup-perks li>span{font:10px var(--mono);color:#35d3e6}.signup-perks strong{display:block;font-family:var(--display);font-size:14px;margin:7px 0;color:#def2f7}.signup-perks p{font-size:12px;line-height:1.6;color:#8facbf}
.signup-console{position:relative;background:linear-gradient(140deg,#10283ad9,#091725f5 75%);border:1px solid #245069;border-radius:8px;padding:28px 30px 0;box-shadow:0 25px 80px #01071066;margin-top:3px;min-width:0}.signup-console::before,.signup-console::after{content:'';position:absolute;width:25px;height:25px;border:2px solid #3ad4e8;pointer-events:none}.signup-console::before{top:-1px;left:-1px;border-right:0;border-bottom:0;border-radius:8px 0 0}.signup-console::after{bottom:-1px;right:-1px;border-left:0;border-top:0;border-radius:0 0 8px}.signup-console-top,.signup-console-bottom{display:flex;justify-content:space-between;align-items:center;font:9px var(--mono);letter-spacing:1.6px;color:#83b5c9}.signup-console-top{margin-bottom:24px}.signup-console-top>span:last-child{font-size:20px;color:#3bd5e9}.signup-console-bottom{border-top:1px solid #1e3e51;margin-top:24px;padding:16px 0;font-size:8px}.signup-mode{display:flex;border:1px solid #25465b;border-radius:5px;padding:4px;background:#050f1d;gap:4px;margin-bottom:30px}.signup-mode button{flex:1;min-width:0;min-height:43px;border:1px solid transparent;border-radius:3px;background:transparent;color:#91acbf;font:600 14px var(--display);padding:10px;cursor:pointer}.signup-mode button[aria-pressed=true]{background:#133448;border-color:#26758c;color:#7de7f2;box-shadow:inset 0 -2px #32cee6}.signup-mode button:hover{color:#dcfaff}.signup-mode button:disabled{opacity:.5;cursor:wait}
.signup-form-heading .kicker{font:9px var(--mono);color:#5bbbd1;letter-spacing:1.5px;margin-bottom:10px}.signup-form-heading h2{font:700 clamp(24px,2.4vw,31px)/1.2 var(--display);letter-spacing:-.6px;margin-bottom:10px}.signup-form-heading p{font-size:13px;line-height:1.7;color:#a3bccb;margin-bottom:24px}.signup-console form{margin:0}.signup-console fieldset{min-width:0;border:0;padding:0;margin:0 0 22px}.signup-console label,.signup-console legend{font-size:12px;color:#b5d0dc;margin-bottom:9px;display:block}.signup-roles{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin-top:8px}.signup-roles label{display:flex;align-items:center;gap:10px;cursor:pointer;border:1px solid #29475c;background:#091827;padding:13px 12px;border-radius:5px;margin:0;min-height:65px}.signup-roles label:has(input:checked){border-color:#30c9e1;background:#0f3143;box-shadow:inset 0 0 18px #1dd4ec08}.signup-roles input{accent-color:#25cfe5;width:16px;height:16px;flex:none;margin:0}.signup-roles strong{display:block;font:600 14px var(--display);color:#e4f7fc}.signup-roles small{display:block;font-size:10px;color:#92b1c3;margin-top:4px;line-height:1.4}.signup-role-note{font-size:10px!important;line-height:1.6!important;color:#87a8bc!important;margin:10px 0 0!important}
.signup-console input[type=email],.signup-console input[type=text],.signup-console input[type=password]{width:100%;min-height:52px;padding:13px 15px;font:15px var(--body);color:#e6f5fa;background:#050e19;border:1px solid #2a495f;border-radius:5px;margin:0 0 20px;box-sizing:border-box}.signup-console input::placeholder{color:#6b889d}.signup-console input:focus-visible{outline:2px solid #3ad9ed;outline-offset:3px;border-color:#3ad9ed}.signup-console #account-code{font:25px var(--mono);letter-spacing:5px}.signup-console .signup-launch{width:100%;min-height:54px;display:flex;align-items:center;justify-content:center;gap:16px;border-radius:5px;font-size:14px;padding:14px 20px}.signup-launch svg{width:21px;height:21px;fill:none;stroke:currentColor;stroke-width:1.6;transition:transform .25s ease}.signup-launch:hover:not(:disabled) svg{transform:translate(3px,-3px)}.signup-console .signup-change{width:100%;margin:12px 0 0;font-size:12px;min-height:42px}.signup-console #account-feedback{margin:16px 0 0;font-size:13px;line-height:1.7;color:#9ce6ef;min-height:0}.signup-console #account-feedback:empty{margin:0}.signup-console #account-feedback[data-state=error]{color:#ffad9b}.signup-console .signup-fine{font-size:11px;line-height:1.7;color:#94b1c4;margin:22px 0 18px}.signup-privacy{border-top:1px solid #224052;padding-top:15px;color:#8caabc;font-size:11px}.signup-privacy summary{cursor:pointer;min-height:28px;color:#b1ccd9}.signup-privacy p{font-size:11px;line-height:1.7;margin-top:10px}.signup-code-address{font:13px var(--mono);overflow-wrap:anywhere;color:#73dbea;margin-bottom:20px}.signup-console [hidden]{display:none!important}
@media(max-width:900px){.signup-layout{grid-template-columns:1fr;gap:30px;max-width:650px;margin:auto}.signup-story{padding:0}.signup-story h1{font-size:46px;letter-spacing:-1.6px;margin:16px 0}.signup-story h1 br{display:none}.signup-story h1 span::before{content:' '}.signup-intro{max-width:none;font-size:14px}.signup-blueprint,.signup-perks{display:none}.signup-console{margin:0}.account-required main{padding:32px 24px 50px}.account-required .flight-deck{padding:0 24px}}
@media(max-width:420px){.account-required main{padding:28px 16px 40px}.account-required .flight-deck{padding:0 16px}.signup-story h1{font-size:39px}.signup-console{padding:22px 20px 0}.signup-roles{gap:8px}.signup-roles label{padding:11px 8px;gap:7px}.signup-mode button{font-size:13px}.signup-console-bottom{letter-spacing:1px}.signup-console .signup-launch{font-size:13px}.account-required .brand{font-size:23px}}
@media(prefers-reduced-motion:reduce){.signup-aircraft,.signup-launch svg{transition:none}.signup-blueprint:hover .signup-aircraft,.signup-launch:hover svg{transform:none}}

/* Password and email verification share the boarding-pass layout. */
.password-input{display:flex;align-items:stretch;gap:8px}.password-input input{min-width:0;flex:1}.password-input button{flex:0 0 auto;margin:0!important;min-width:68px}.signup-console #confirm-password-field{margin-top:14px}.signup-console #recovery-form{display:grid;gap:12px}.signup-console #recovery-form[hidden]{display:none}.signup-console #recovery-details{display:grid;gap:10px}.signup-console #recovery-details[hidden]{display:none}.signup-console #recovery-help{color:var(--muted,#9eb1c6);font-size:.9rem;line-height:1.6}

.signup-console .password-input{margin-bottom:12px}.signup-console .password-input input{margin-bottom:0}.signup-console #password-fields{margin-bottom:20px}

/* learning.css */
.learning-platform{--learn-cyan:#6ce2ff;--learn-border:rgba(120,191,224,.22);--learn-panel:rgba(9,22,40,.94);max-width:1360px;margin:auto}.learning-platform h1,.learning-platform h2,.learning-platform h3{letter-spacing:-.025em}.learning-platform p{color:#b8cbdc;line-height:1.7}.learning-hero{position:relative;display:grid;grid-template-columns:1.45fr 1fr;align-items:center;overflow:hidden;border:1px solid var(--learn-border);border-radius:24px;padding:clamp(25px,4vw,60px);background:radial-gradient(ellipse at 85% 40%,#16466890,transparent 60%),linear-gradient(140deg,#0b1e36,#06101e);isolation:isolate}.learning-hero:before{content:"";position:absolute;inset:0;background-image:linear-gradient(#6ce2ff07 1px,transparent 1px),linear-gradient(90deg,#6ce2ff07 1px,transparent 1px);background-size:40px 40px;z-index:-1}.learning-hero h1{font-size:clamp(36px,4.6vw,68px);line-height:1.05;margin:20px 0;max-width:650px}.learning-hero h1 em{font-style:normal;color:var(--learn-cyan)}.learning-hero p{max-width:520px;font-size:17px}.learning-hero-actions,.learning-inline-links,.unit-game-links,.unit-sim-options{display:flex;gap:12px;flex-wrap:wrap;margin-top:22px}.learning-orbit{height:290px;position:relative;display:flex;align-items:center;justify-content:center}.learning-orbit i{position:absolute;width:85%;height:40%;border:1px solid #67d9fb88;border-radius:50%;box-shadow:0 0 35px #2aa2cf14;transform:rotate(-35deg)}.learning-orbit i:nth-child(2){transform:rotate(35deg)}.learning-orbit i:nth-child(3){transform:rotate(90deg)}.learning-orbit i:after{content:"";position:absolute;left:20%;top:2%;width:13px;height:13px;border-radius:50%;background:#b1f0ff;box-shadow:0 0 24px #55ceff}.learning-orbit strong{font-size:40px;color:#d3f5ff;text-shadow:0 0 40px #60c1ff}.learning-orbit>span{position:absolute;bottom:-5px;font-size:10px;letter-spacing:2.5px;color:#75abc6}.learning-overview{display:grid;grid-template-columns:repeat(4,1fr);gap:1px;background:var(--learn-border);border:1px solid var(--learn-border);border-radius:14px;overflow:hidden;margin:22px 0 30px}.learning-overview>span{padding:20px;background:#0c1b2c;color:#9eb4c9;font-size:13px}.learning-overview b{font-size:25px;color:#e6f7ff;margin-right:10px}.learning-stage-tabs{display:flex;gap:9px;flex-wrap:wrap;margin:24px 0 32px}.learning-stage-tabs button{display:flex;gap:10px;align-items:center;border:1px solid var(--learn-border);border-radius:10px;padding:12px 17px;background:#0a192b;color:#bfd1e2;cursor:pointer}.learning-stage-tabs button[aria-pressed=true]{background:#123a50;border-color:#62d7fa;color:white;box-shadow:0 0 0 1px #62d7fa22}.learning-stage-tabs small{color:#68d3f3;font-family:monospace}.learning-catalog-tools{display:flex;align-items:end;gap:20px;justify-content:space-between}.learning-catalog-tools h2{font-size:24px;margin:7px 0}.learning-catalog-tools label{font-size:12px;color:#b9cbdc;display:grid;gap:6px}.learning-catalog-tools input,.learning-catalog-tools select{width:100%;min-width:180px}.learning-platform input,.learning-platform select,.learning-platform textarea{font:inherit;background:#061221;border:1px solid #2f4b65;border-radius:9px;color:#eaf6ff;padding:12px}.learning-platform textarea{resize:vertical;max-width:100%;width:100%}.learning-platform input:focus,.learning-platform textarea:focus,.learning-platform select:focus{outline:2px solid #62d7fa;outline-offset:2px}#learning-count{font-size:12px;margin:20px 0}.learning-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:20px}.learning-card{color:inherit;text-decoration:none;border:1px solid var(--learn-border);border-radius:15px;overflow:hidden;background:var(--learn-panel);display:flex;flex-direction:column;transition:transform .2s,border-color .2s,box-shadow .2s}.learning-card:hover{transform:translateY(-4px);border-color:#6cd9f6;box-shadow:0 18px 35px #0004}.learning-card-band{display:flex;justify-content:space-between;align-items:center;padding:20px;background:linear-gradient(120deg,#144955,#0d2639);font-size:11px;letter-spacing:1px;text-transform:uppercase;color:#c8f8ff}.learning-card-band>span:last-child{font:600 27px monospace;opacity:.65}.igcse .learning-card-band,.unit-hero.igcse{background:linear-gradient(120deg,#293b69,#111e36)}.as .learning-card-band,.unit-hero.as{background:linear-gradient(120deg,#41365d,#191c33)}.a2 .learning-card-band,.unit-hero.a2{background:linear-gradient(120deg,#4d3842,#1c2132)}.learning-card-body{padding:22px;display:flex;flex:1;flex-direction:column}.learning-card-status{font-size:11px;color:#82c4d6;display:flex;gap:10px;justify-content:space-between}.learning-card h2{font-size:22px;line-height:1.25;margin:16px 0 10px}.learning-card p{font-size:13px;margin:0 0 24px;flex:1}.learning-card-bottom{font-size:10px;display:flex;justify-content:space-between;align-items:center;border-top:1px solid var(--learn-border);padding-top:15px;color:#9fb5c9}.learning-card-bottom b{font-size:21px;color:#7ee7ff}.learning-scope{margin-top:35px;padding:28px;border:1px solid var(--learn-border);border-radius:15px}.learning-scope h2{font-size:22px}.learning-scope p{font-size:13px}.learning-empty{grid-column:1/-1;text-align:center;padding:70px 20px}.unit-breadcrumb{display:flex;flex-wrap:wrap;gap:10px;margin:5px 0 22px;font-size:12px;color:#849db5}.unit-breadcrumb a{color:#8ed8ed}.unit-hero{display:flex;justify-content:space-between;align-items:center;gap:25px;background:linear-gradient(120deg,#143e4b,#0d2032);border:1px solid var(--learn-border);border-radius:18px;padding:32px}.unit-hero h1{font-size:clamp(30px,3.5vw,48px);margin:12px 0}.unit-hero p{margin:0;max-width:720px}.unit-hero-actions{display:flex;flex-wrap:wrap;gap:10px;flex-shrink:0;max-width:230px}.unit-hero-actions button{width:100%}.unit-layout{display:grid;grid-template-columns:230px minmax(0,1fr);gap:30px;margin-top:30px}.unit-sidebar{min-width:0;align-self:start;position:sticky;top:20px}.unit-sidebar nav{display:grid;gap:5px;margin:15px 0 20px;max-height:65vh;overflow:auto;padding:3px}.unit-sidebar nav a{display:flex;align-items:center;gap:9px;color:#a7bbce;text-decoration:none;font-size:12px;padding:11px;border-radius:8px}.unit-sidebar nav a>span{font-family:monospace;opacity:.6}.unit-sidebar nav a[aria-current=page]{background:#15364a;color:#adf2ff;box-shadow:inset 2px 0 #73dbf7}.unit-sidebar nav a:hover{background:#142a40}.unit-sidebar b{margin-left:auto;color:#84e4ab}.unit-main{min-width:0}.unit-tabs{display:flex;gap:4px;border-bottom:1px solid var(--learn-border);overflow-x:auto;padding:0 0 12px;margin-bottom:22px}.unit-tabs a{flex-shrink:0;padding:11px 14px;text-decoration:none;font-size:13px;color:#a6bfd6;border-radius:8px}.unit-tabs a[aria-current=page]{background:#174254;color:#b7f5ff}.unit-section,.unit-notes{border:1px solid var(--learn-border);border-radius:14px;background:var(--learn-panel);padding:clamp(20px,3vw,35px);margin-bottom:20px}.unit-section>h2{font-size:clamp(23px,2.5vw,31px);line-height:1.25;margin:12px 0 20px}.unit-section li{color:#b9cce0;line-height:1.7;margin:7px 0}.unit-objectives,.unit-investigation,.unit-example,.unit-exam-method{padding:22px;background:#10263b;border-radius:10px;margin:24px 0}.unit-equations{display:grid;gap:10px}.unit-equations>div{padding:20px;background:#071526;border:1px solid #234259;border-radius:10px}.unit-equations strong{font-family:monospace;color:#8be7ff;font-size:18px}.unit-equations p{font-size:13px;margin:8px 0 0}.unit-pitfall{padding:18px 20px;border-left:3px solid #f5bf7e;background:#382f252d}.unit-pitfall strong{color:#f5cc99}.unit-pitfall p{margin:5px 0;font-size:14px}.unit-section summary{cursor:pointer;color:#82dcf8;padding:12px 0}.unit-resource-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:18px}.unit-resource{border:1px solid #2c445d;border-radius:12px;padding:24px;background:#0c1d31}.unit-resource small{color:#9fc7dc;display:block}.unit-resource h3{font-size:23px;line-height:1.3}.unit-resource p{font-size:13px}.resource-symbol{display:grid;place-items:center;width:55px;height:55px;background:#43353e;border:1px solid #98667e;border-radius:16px;color:#ffd6df;font-size:21px;margin-bottom:20px}.unit-notes label{font-size:12px;color:#a8c2d8;display:block;margin:16px 0 8px}.unit-notes p{font-size:13px}.unit-notes button{margin-top:12px}.unit-notes h2{font-size:24px}.unit-exam-list{display:grid;gap:14px}.unit-exam-list article{padding:20px;border:1px solid #2b435a;border-radius:12px;display:flex;justify-content:space-between;align-items:center;gap:20px}.unit-exam-list h3{font-size:17px;margin:0 0 10px}.unit-exam-list code{font-size:12px;overflow-wrap:anywhere}.unit-exam-list ul{padding-left:18px}.unit-exam-list a{flex-shrink:0}.unit-exam-list p{font-size:13px}.unit-answer{display:flex;gap:12px;align-items:center;border:1px solid #294056;background:#0b1d30;border-radius:8px;padding:13px;margin:9px 0;cursor:pointer}.unit-answer:has(input:checked){border-color:#75def7;background:#153347}.unit-answer input{accent-color:#5ad7f7;flex-shrink:0}.unit-answer span{font-size:14px;color:#cfdfed}#unit-quiz fieldset{border:0;padding:0;margin:25px 0 35px}#unit-quiz legend{font-size:17px;line-height:1.5;margin-bottom:10px}#unit-quiz fieldset p{font-size:13px}#unit-share-panel:not([hidden]){padding:25px;border:1px solid #70d7ef;border-radius:12px;margin-top:20px;background:#0c2536}#unit-share-form{display:grid;gap:14px;max-width:750px}#unit-share-form label{display:grid;gap:6px}#unit-phet .phet-followup{display:none}.unit-sim-options button[aria-pressed=true]{border-color:#70e0ff;background:#1a4056}.unit-sim-options{margin-bottom:5px}.unit-phet .phet-detail-heading h2{font-size:24px}.room-tabs button{min-width:110px}.classroom-heading{border:1px solid #36617f;border-radius:18px;padding:30px;background:linear-gradient(110deg,#153c54,#101d33)}.room-header{background:linear-gradient(120deg,#143a50,#121e31);padding:24px;border-radius:12px}.resource-feed .class-post{border-left:3px solid #56bfd7}.learning-platform :focus-visible{outline:2px solid #8ce8ff;outline-offset:3px}
@media(max-width:1050px){.learning-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.learning-catalog-tools{flex-wrap:wrap}.learning-catalog-tools>div{width:100%}.unit-layout{grid-template-columns:190px minmax(0,1fr);gap:18px}.unit-resource-grid{grid-template-columns:1fr}.unit-exam-list article{align-items:start;flex-direction:column}.unit-hero-actions{max-width:180px}}
@media(max-width:700px){.learning-hero{grid-template-columns:1fr}.learning-orbit{display:none}.learning-hero h1{font-size:39px}.learning-overview{grid-template-columns:repeat(2,1fr)}.learning-overview>span{padding:15px}.learning-grid{grid-template-columns:1fr}.learning-stage-tabs{gap:7px}.learning-stage-tabs button{font-size:12px;padding:10px}.learning-stage-tabs small{display:none}.learning-catalog-tools label{width:100%}.unit-layout{grid-template-columns:minmax(0,1fr)}.unit-sidebar{position:static}.unit-sidebar nav{display:flex;max-height:none;overflow:auto}.unit-sidebar nav a{flex-shrink:0;max-width:210px}.unit-sidebar>a{display:none}.unit-hero{flex-direction:column;align-items:start;padding:24px}.unit-hero-actions{max-width:none}.unit-hero-actions button{width:auto}.unit-tabs a{padding:10px;font-size:12px}.learning-hero-actions{gap:8px}.learning-hero-actions a{font-size:13px}.learning-scope{padding:20px}.unit-section{padding:20px}.unit-equations strong{font-size:15px;overflow-wrap:anywhere}.learning-card h2{font-size:23px}}
@media(prefers-reduced-motion:reduce){.learning-card{transition:none}.learning-card:hover{transform:none}}
.book-shelf{margin:40px 0;padding:32px;border:1px solid #28485d;border-radius:18px;background:#091a2b}.book-shelf>h2{font-size:32px;margin:12px 0}.book-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:22px;margin-top:28px}.book-card{display:grid;grid-template-columns:145px minmax(0,1fr);gap:20px;padding:20px;border:1px solid #284156;border-radius:13px;background:#0c2032}.book-card h3{margin:12px 0;font-size:21px}.book-card p{font-size:12px}.book-card small{color:#a4d9e7;font-size:11px}.book-spine{min-height:220px;padding:20px 14px;display:flex;flex-direction:column;gap:18px;background:linear-gradient(110deg,#17485d 6%,#102f45 8%,#285e70);border-radius:3px 10px 10px 3px;box-shadow:5px 8px 18px #0004}.book-spine strong{font-size:20px;line-height:1.25}.book-spine span{font-size:10px;text-transform:uppercase;letter-spacing:1px}.book-spine small{margin-top:auto}.book-1{background:linear-gradient(110deg,#333562 6%,#222540 8%,#4b477d)}.book-2{background:linear-gradient(110deg,#553d28 6%,#35291e 8%,#6a5743)}.book-3{background:linear-gradient(110deg,#264e43 6%,#19362e 8%,#3b6d5e)}.book-4{background:linear-gradient(110deg,#274560 6%,#162d43 8%,#3a6587)}.depth-map{display:grid;gap:8px;padding:20px;background:#071725;border-radius:10px}.depth-map a{font-size:13px;color:#92dcf2;text-decoration:none;padding:5px}.unit-depth article{scroll-margin-top:25px;padding:28px 0;border-bottom:1px solid #284258}.unit-depth article h3{font-size:23px;margin:10px 0 14px}.depth-number{font:18px monospace;color:#70d9f5}.unit-depth article p{font-size:15px;max-width:78ch}.explain-check{padding:14px 20px;background:#142f40;border-radius:12px}.unit-understood{padding:24px;margin:25px 0;border:1px solid #387062;border-radius:14px;background:#102d2b}.unit-understood h2{font-size:23px}.unit-understood p{font-size:13px}.unit-understood button[aria-pressed=true]{background:#235a48;border-color:#8ad8b2}.unit-understood>a{display:inline-block;margin:12px 0;color:#9de4df}.stats-hero{grid-template-columns:1fr}.stats-scope{font-size:13px;padding:0 10px 25px}.stage-stat-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:16px}.stage-stat-grid article{padding:18px;border:1px solid #2d4b63;border-radius:12px;background:#0b2032}.stage-stat-grid h3{font-size:20px}.stage-stat-grid p{font-size:12px}.stage-stat-grid progress{width:100%;height:12px;accent-color:#7ce0ef}.stats-table-wrap{overflow-x:auto}.study-table{width:100%;border-collapse:collapse;font-size:13px;text-align:left}.study-table td,.study-table th{padding:14px 12px;border-bottom:1px solid #28445a;white-space:nowrap}.study-table th:first-child{white-space:normal;min-width:180px}.study-table a,.attempt-history a{color:#9ce3f5}.attempt-history{padding:0;list-style:none}.attempt-history li{display:flex;justify-content:space-between;align-items:center;gap:20px;padding:18px 0;border-bottom:1px solid #29495e}.attempt-history p{font-size:13px;margin:6px 0}.attempt-history small{font-size:11px;color:#a3bbcd}.attempt-history strong{font:24px monospace;white-space:nowrap}.exam-timer-panel{background:linear-gradient(120deg,#153d50,#15263a);border:1px solid #56bfd7;border-radius:14px;padding:24px;margin:25px 0;display:grid;grid-template-columns:1fr auto;gap:12px}.exam-timer-panel h3{font-size:19px;margin:10px 0;overflow-wrap:anywhere}.exam-timer-panel output{font:42px monospace;color:#abf1ff;align-self:center}.exam-timer-panel p{font-size:12px;margin:6px 0}.exam-timer-panel>.subtle,.exam-timer-panel>#exam-topic-total,.exam-timer-controls{grid-column:1/-1}.exam-timer-controls{display:flex;flex-wrap:wrap;gap:10px;margin:12px 0}.exam-resource-actions{min-width:0;max-width:100%;display:grid;gap:14px}.timed-question-buttons{display:grid;gap:8px}.timed-question-buttons button{font-size:12px;text-align:left;white-space:normal;overflow-wrap:anywhere;line-height:1.6}.unit-exam-list article{align-items:start}.simulation-guidance{padding:16px;border-left:2px solid #75d9f0;background:#0e2d3f}
/* Classroom workspace: full-height classwork board with an in-place topic library. */
.classroom-layout{grid-template-columns:245px minmax(0,1fr);gap:26px}.classroom-main{min-height:780px;padding:28px;min-width:0}.classroom-sidebar{position:sticky;top:20px}.room-banner{position:relative;min-height:180px;align-items:center;padding:35px;border-radius:16px;background:radial-gradient(ellipse at 85% 10%,#255c78aa,transparent 60%),linear-gradient(120deg,#133244,#181d39);overflow:hidden}.room-banner:after{content:"";position:absolute;right:-40px;top:-90px;width:350px;height:350px;border:1px solid #85caff25;border-radius:50%;pointer-events:none;box-shadow:0 0 0 35px #85caff07,0 0 0 70px #85caff05}.room-banner h2{font-size:clamp(26px,3vw,42px)}.room-tabs{gap:12px;margin:26px 0}.room-tabs button{padding:14px 26px}.room-tabs button[aria-pressed=true]{background:#164259;border:1px solid #4f9bb7;color:#c6f4ff}.resource-intro h3{font-size:28px;margin:12px 0}.resource-intro p{max-width:720px;line-height:1.7}.classroom-layout .resource-feed{max-height:none;overflow:visible;gap:12px;padding:0;margin-bottom:30px}.classwork-library{margin:26px 0;border:1px solid #477e96;background:#102b3d;border-radius:14px;overflow:hidden}.classwork-library>summary{cursor:pointer;padding:20px 22px;list-style:none;display:flex;justify-content:space-between;gap:20px;align-items:center}.classwork-library>summary>span{color:#b0ecfa;font-weight:700;font-size:17px}.classwork-library>summary small{font-size:11px;color:#aac3d3}.classwork-library-body{padding:0 22px 22px}.classwork-search-row{display:flex;align-items:end;gap:16px;flex-wrap:wrap}.classwork-search-row label{display:grid;gap:6px;flex:1;font-size:12px;min-width:140px}.classwork-search-row select,.classwork-search-row input{margin:0;width:100%}.classwork-search-row>p{font-size:12px;width:100%;margin:0 0 10px}.classwork-library #classwork-topic-count{font-size:12px;color:#b0c9d8}.classwork-picker{display:grid;grid-template-columns:1fr 1fr;gap:20px}.classwork-topic-results{display:grid;gap:8px;max-height:480px;overflow:auto;align-content:start;padding-right:5px}.topic-pick{padding:15px;background:#0b1e30;border:1px solid #2c5066;border-radius:10px;display:grid;gap:6px;text-align:left;color:#d4ebf5;cursor:pointer}.topic-pick small{color:#8cc9e0;font-size:10px}.topic-pick span{color:#8fcddd;font-size:11px}.topic-pick[aria-pressed=true]{background:#19445a;border-color:#87def4}.classwork-topic-preview{padding:22px;background:#091c2c;border:1px solid #335d74;border-radius:12px;align-self:start;overflow-wrap:anywhere}.classwork-topic-preview h3{font-size:23px;line-height:1.25}.classwork-topic-preview p,.classwork-topic-preview li{font-size:13px;line-height:1.7;color:#b7d0e0}.classwork-topic-preview ul{padding-left:20px}.classwork-topic-preview .quiet,.classwork-topic-preview .primary{margin:6px 0;width:100%;font-size:12px;white-space:normal}.classwork-feed-tools{padding:20px 0}.classwork-topic-tag{font-size:11px;letter-spacing:.4px;color:#9fdaed;margin:18px 0 0}.room-composer{background:#0d2536;border:1px solid #2f566c;border-radius:14px;padding:24px!important}.room-feed .class-post{padding:22px}.classroom-heading{padding:38px}.classroom-tools{margin-top:24px}.classroom-main :focus-visible{outline:2px solid #8ce8ff;outline-offset:3px}
@media(max-width:1100px){.book-grid{grid-template-columns:1fr}.stage-stat-grid{grid-template-columns:repeat(2,1fr)}.classroom-layout{grid-template-columns:200px minmax(0,1fr)}.classroom-main{padding:20px}.classwork-picker{grid-template-columns:1fr}.classwork-topic-results{max-height:280px}.classwork-library>summary{align-items:start;flex-direction:column;gap:8px}}
@media(max-width:800px){.classroom-layout{grid-template-columns:1fr}.classroom-sidebar{position:static}.classroom-main{padding:18px}.room-banner{padding:25px;min-height:160px}.classroom-heading{padding:25px}.book-shelf{padding:22px}.exam-timer-panel{grid-template-columns:1fr}.exam-timer-panel output{font-size:36px}.book-card{grid-template-columns:110px minmax(0,1fr);padding:15px;gap:16px}.book-spine{padding:15px 10px;min-height:180px}.book-spine strong{font-size:16px}.unit-depth article h3{font-size:21px}.classwork-library-body{padding:0 14px 18px}}
@media(max-width:450px){.book-card{grid-template-columns:1fr}.book-spine{min-height:130px}.book-spine strong{font-size:21px}.stage-stat-grid{grid-template-columns:1fr}.room-tabs button{min-width:0;padding:12px}.classwork-search-row{display:grid;grid-template-columns:1fr}.exam-timer-controls .quiet{font-size:12px}.unit-depth article p{font-size:14px}}

.subject-grid{margin:30px 0}.aero-subnav{display:flex;gap:10px;flex-wrap:wrap;padding:16px 0 24px}.aero-subnav a{padding:10px 14px;border:1px solid #35617a;border-radius:10px;background:#102739;color:#bce9f5;text-decoration:none}.study-sharing{display:flex;align-items:center;gap:10px;line-height:1.5;margin:22px 0}.study-sharing input{width:auto}.study-table small{font-size:10px;color:#87bdcf}.room-subject-stats{margin-top:28px}

/* study-viewer.css */
.study-viewer{margin:1.25rem 0;padding:1.25rem;border:1px solid var(--line,#cbd5e1);border-radius:18px;background:var(--panel,#102030);color:var(--text,#edf5fc)}
.study-viewer[hidden]{display:none}.study-viewer header{display:flex;align-items:center;justify-content:space-between;gap:1rem}.study-viewer h3{margin:0}.study-viewer iframe{display:block;width:100%;min-height:240px;aspect-ratio:16/9;border:0;border-radius:12px;background:#142027}.study-viewer-timer{display:flex;align-items:center;gap:.75rem;flex-wrap:wrap;padding:1rem 0}.study-viewer-timer output{font-variant-numeric:tabular-nums}.study-viewer button{padding:.55rem .85rem;border-radius:9px;cursor:pointer}.study-viewer button:disabled{opacity:.55;cursor:default}.study-viewer a{overflow-wrap:anywhere}.study-viewer-disclosure{font-size:.85rem;line-height:1.5;opacity:.8}.study-viewer [data-study-status]{font-size:.85rem}.study-viewer button:focus-visible,.study-viewer a:focus-visible{outline:3px solid #128c89;outline-offset:3px}@media(max-width:480px){.study-viewer{padding:.85rem}.study-viewer iframe{min-height:210px}}

.study-viewer button{color:var(--text,#edf5fc);background:#183746;border:1px solid #43717e}.study-viewer button:hover:not(:disabled){background:#245268}.study-viewer-timer output{color:#a6efff;font:600 1.6rem monospace}.study-viewer h3{color:var(--text,#edf5fc)}

/* subject-labs.css */
.subject-lab{padding:1.25rem;border:1px solid var(--border,#31536c);border-radius:12px;background:var(--panel,#101f34);margin-block:1.2rem}.subject-lab p{max-width:78ch;line-height:1.65}.subject-lab-controls{display:flex;flex-wrap:wrap;gap:1rem;align-items:center}.subject-lab label{display:inline-flex;align-items:center;flex-wrap:wrap;gap:.6rem;margin:.5rem .75rem .5rem 0}.subject-lab input[type=number]{width:7rem}.subject-lab input,.subject-lab select{max-width:100%;accent-color:#37d8ed}.subject-lab input[type=range]{width:min(12rem,50vw)}.subject-lab output{font-variant-numeric:tabular-nums;min-width:2ch}.subject-lab svg{display:block;width:100%;max-width:700px;border:1px solid #31536c;margin-block:1rem;background:#0a1524;overflow:hidden}.subject-lab table{border-collapse:collapse;min-width:12rem;margin-block:1rem}.subject-lab th,.subject-lab td{padding:.4rem .8rem;border:1px solid #31536c;text-align:center}.subject-lab caption{text-align:left;padding:.5rem 0}.subject-lab :focus-visible{outline:3px solid #37d8ed;outline-offset:3px}.subject-lab [data-trace]{font-family:var(--mono,monospace);line-height:1.7}

/* design-system.css */
/* AeroLab 31 · shared tokens. All foreground/background pairs are checked in
   work/check-design-system.mjs. System fonts avoid a blocking font download. */
:root{
 --color-bg:#07111f;--color-surface:#0d1b2c;--color-raised:#13243a;--color-hover:#1a3048;
 --color-border:#2b4159;--color-control-border:#627a95;--color-text:#eef4fc;--color-muted:#a4b4ca;
 --color-primary:#63d8e8;--color-primary-hover:#92e8f3;--color-on-primary:#07111f;
 --color-physics:#63d8e8;--color-math:#b9a2ff;--color-chemistry:#80dfbd;--color-computing:#8fbaff;--color-biology:#c1de84;
 --color-success:#80dfb1;--color-warning:#f3ce83;--color-error:#ffa6ae;
 --font-ui:Inter,ui-sans-serif,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;
 --font-mono:ui-monospace,"SFMono-Regular",Consolas,"Liberation Mono",monospace;
 --text-xs:.75rem;--text-sm:.875rem;--text-base:1rem;--text-lg:1.125rem;--text-xl:1.375rem;--text-2xl:1.875rem;--text-3xl:2.75rem;--text-4xl:3.5rem;
 --space-1:.25rem;--space-2:.5rem;--space-3:.75rem;--space-4:1rem;--space-5:1.25rem;--space-6:1.5rem;--space-8:2rem;--space-10:2.5rem;--space-12:3rem;--space-16:4rem;
 --radius-sm:6px;--radius-md:10px;--radius-lg:16px;--radius-pill:999px;
 --shadow-sm:0 2px 8px #0002;--shadow-lg:0 16px 40px #0003;
 --motion-fast:140ms;--motion-page:180ms;--page-width:1200px;--subject-accent:var(--color-physics);
 /* Compatibility aliases keep the existing simulations and account screens coherent. */
 --bg:var(--color-bg);--panel:var(--color-surface);--line:var(--color-border);--text:var(--color-text);--muted:var(--color-muted);--cyan:var(--color-primary);--mono:var(--font-mono);
 color-scheme:dark;font-family:var(--font-ui);font-size:16px;
}
html{scroll-padding-top:90px;background:var(--color-bg)}
body{background:var(--color-bg);color:var(--color-text);font-family:var(--font-ui);line-height:1.6;letter-spacing:0}
body::before,body::after{display:none}
*,*::before,*::after{box-sizing:border-box}
[hidden]{display:none!important}
h1,h2,h3,h4{font-family:var(--font-ui);color:var(--color-text);font-weight:650;letter-spacing:-.025em;line-height:1.2}
h1{font-size:clamp(2rem,4.2vw,var(--text-3xl))}h2{font-size:clamp(1.3rem,2.5vw,var(--text-2xl))}h3{font-size:var(--text-lg)}
p{color:var(--color-muted);line-height:1.65}strong{font-weight:650}small{font-size:var(--text-xs)}
a{color:inherit;text-decoration:none}a:hover{color:var(--color-primary-hover)}
button,input,select,textarea{font:inherit}button,input,select{min-height:44px}button{color:var(--color-text)}
button,a,input,select,textarea,summary{touch-action:manipulation}
:where(a,button,input,select,textarea,summary):focus-visible{outline:3px solid var(--color-primary);outline-offset:4px;box-shadow:none}
.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-link{position:fixed;top:8px;left:12px;z-index:1000;transform:translateY(-160%);padding:12px 18px;background:var(--color-primary);color:var(--color-on-primary)}.skip-link:focus{transform:none}
.primary,.quiet{display:inline-flex;align-items:center;justify-content:center;gap:10px;min-height:44px;padding:11px 18px;font-size:var(--text-sm);font-family:var(--font-ui);font-weight:600;border-radius:var(--radius-md);text-decoration:none;line-height:1.4;transition:background var(--motion-fast),border-color var(--motion-fast);box-shadow:none;transform:none}
.primary{background:var(--color-primary);color:var(--color-on-primary);border:1px solid var(--color-primary)}
.primary:hover:not(:disabled){background:var(--color-primary-hover);border-color:var(--color-primary-hover);color:var(--color-on-primary);transform:none}
.quiet{background:var(--color-surface);border:1px solid var(--color-control-border);color:var(--color-text)}
.quiet:hover:not(:disabled){background:var(--color-hover);border-color:var(--color-primary);color:var(--color-text);transform:none}
button:disabled{opacity:.55;cursor:not-allowed}.quiet[aria-pressed=true]{color:var(--color-primary);border-color:var(--color-primary);background:#123445}
.text-link{display:inline-flex;align-items:center;gap:8px;min-height:44px;color:var(--color-primary);font-size:var(--text-sm);font-weight:600}
label{color:var(--color-text);font-size:var(--text-sm)}input:not([type=checkbox]):not([type=radio]):not([type=range]),select,textarea{padding:11px 13px;border:1px solid var(--color-control-border);border-radius:var(--radius-md);background:var(--color-bg);color:var(--color-text);max-width:100%;min-width:0;box-shadow:none}
input::placeholder,textarea::placeholder{color:var(--color-muted);opacity:1}input[type=checkbox],input[type=radio]{accent-color:var(--color-primary);width:18px;height:18px;min-height:18px;flex-shrink:0}input[aria-invalid=true]{border-color:var(--color-error)}
input:disabled,select:disabled{opacity:.6}summary{cursor:pointer;min-height:44px;padding-block:12px;color:var(--color-text)}
.kicker,.eyebrow{display:block;font:600 .68rem/1.5 var(--font-mono);letter-spacing:.11em;color:var(--color-muted);text-transform:uppercase;margin-bottom:12px}.eyebrow i{display:inline-block;width:6px;height:6px;border-radius:50%;background:var(--color-primary);margin-right:8px}
.subtle,.resource-note{color:var(--color-muted);font-size:var(--text-xs)}
progress{appearance:none;width:100%;height:4px;border:0;border-radius:4px;background:var(--color-border);accent-color:var(--subject-accent)}progress::-webkit-progress-bar{border-radius:4px;background:var(--color-border)}progress::-webkit-progress-value{border-radius:4px;background:var(--subject-accent)}progress::-moz-progress-bar{border-radius:4px;background:var(--subject-accent)}
/* App chrome stays compact; all subjects share one navigation system. */
.topbar{max-width:none;margin:0;padding:14px max(20px,calc((100vw - var(--page-width))/2));display:flex;align-items:center;gap:24px;flex-wrap:nowrap;background:var(--color-bg);border:0;border-bottom:1px solid var(--color-border);border-radius:0;box-shadow:none;position:relative;z-index:20}
.brand{font:700 22px/1 var(--font-ui);letter-spacing:-.06em;display:inline-flex;gap:9px;align-items:center;margin:0;white-space:nowrap}.brand-mark{display:grid;place-items:center;width:34px;height:34px;border:1px solid #407a89;border-radius:9px;color:var(--color-primary);background:#102d3c}.brand svg{width:23px;height:23px}.brand .cyan{color:var(--color-text)}
.topbar .desktop-nav{display:flex;gap:4px;padding:0;background:none;border:0;flex:1;justify-content:center;flex-wrap:nowrap}
.topbar nav a{min-height:44px;padding:12px 13px;border:0;border-radius:var(--radius-sm);font-size:var(--text-sm);color:var(--color-muted);white-space:nowrap;background:none;box-shadow:none}
.topbar nav a[aria-current=page]{background:var(--color-raised);color:var(--color-text)}.topbar nav a[aria-current=page]::after{display:none}.topbar nav a:hover{background:var(--color-surface);color:var(--color-text)}
.subject-switch{margin-left:auto;max-width:170px;display:block}.subject-switch select{font-size:var(--text-sm);width:100%;padding-right:22px;background:var(--color-surface);border-color:var(--color-border)}
.shell-account{display:inline-flex;align-items:center;gap:7px;min-height:44px;font-size:var(--text-sm);color:var(--color-muted)}.shell-account span{display:none}.shell-language{display:none}
main#page-content{width:100%;max-width:var(--page-width);padding:40px 24px 72px;margin:auto;min-height:65vh}
.mobile-nav{display:none}.site-footer{border-top:1px solid var(--color-border);max-width:var(--page-width);margin:0 auto;padding:28px 24px;display:grid;grid-template-columns:1fr auto;gap:20px;background:none}.site-footer p{font-size:var(--text-xs);margin-top:12px}.site-footer nav{display:flex;flex-wrap:wrap;align-items:center;gap:6px 20px;font-size:var(--text-xs)}.site-footer nav a{min-height:44px;display:inline-flex;align-items:center}.site-footer small{color:var(--color-muted);grid-column:1/-1}
.environment-controls{display:none}.aero-subnav{display:flex;flex-wrap:wrap;gap:8px;margin:0 0 24px;padding:12px;background:var(--color-surface);border:1px solid var(--color-border);border-radius:var(--radius-md)}.aero-subnav a{font-size:var(--text-sm);padding:8px 12px;min-height:44px}
/* Homepage: a small original vector model adds context without a media download. */
.learning-home{display:grid;gap:48px}.home-hero{display:grid;grid-template-columns:1.35fr 1fr;align-items:center;gap:48px;padding:32px 0 12px}.home-hero h1{font-size:clamp(2rem,4.2vw,3.5rem);max-width:690px;line-height:1.12;letter-spacing:-.045em}.home-hero h1 span{color:var(--color-text)}.home-hero p{font-size:var(--text-base);max-width:490px;margin:22px 0 24px}.home-hero small{display:block;margin-top:16px;color:var(--color-muted);line-height:1.5}.hero-model{background:var(--color-surface);border:1px solid var(--color-border);border-radius:var(--radius-lg);padding:20px;transform:rotate(-2deg);box-shadow:var(--shadow-lg)}.hero-model svg{width:100%;height:auto;display:block;margin-block:16px}.model-heading,.model-footer{display:flex;align-items:center;justify-content:space-between;gap:12px;font:11px/1.5 var(--font-mono);color:var(--color-muted)}.model-heading span:last-child{color:var(--color-primary)}.model-footer b{font-size:18px;color:var(--color-primary);white-space:nowrap}
.section-heading{display:flex;justify-content:space-between;align-items:end;gap:16px;margin-bottom:20px}.section-heading .eyebrow{margin-bottom:8px}.section-heading h2{font-size:24px}.path-grid,.simulation-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}.path-card{display:flex;align-items:start;gap:14px;border:1px solid var(--color-border);border-radius:var(--radius-md);padding:22px;background:var(--color-surface);transition:border-color var(--motion-fast),background var(--motion-fast)}.path-card:hover,.subject-choice:hover{border-color:var(--color-primary);background:var(--color-raised)}.path-number{font:13px var(--font-mono);color:var(--color-primary);padding-top:4px}.path-card>svg{flex-shrink:0;margin-left:auto}.path-card small{color:var(--color-muted);font-size:11px}.path-card h3{margin:4px 0 10px;font-size:20px}.path-card p{font-size:13px;line-height:1.6}
.home-continue{display:flex;align-items:center;gap:20px;padding:24px;border:1px solid #315764;border-radius:var(--radius-lg);background:#102732}.home-continue .continue-icon{display:grid;place-items:center;width:52px;height:52px;border:1px solid #315764;border-radius:12px;color:var(--color-primary);flex-shrink:0}.home-continue>div:nth-child(2){flex:1}.home-continue h2{font-size:20px}.home-continue p{font-size:13px;margin-top:6px}.home-continue .eyebrow{margin-bottom:6px}.home-continue .primary{flex-shrink:0}
.simulation-card{overflow:hidden;background:var(--color-surface);border:1px solid var(--color-border);border-radius:var(--radius-md);transition:border-color var(--motion-fast)}.simulation-card:hover{border-color:var(--color-primary)}.simulation-thumbnail{height:145px;background:linear-gradient(135deg,#142f40,#0b192a);display:flex;align-items:center;justify-content:center;gap:22px;color:var(--color-primary);position:relative;border-bottom:1px solid var(--color-border)}.simulation-thumbnail>span{font:22px var(--font-mono)}.simulation-thumbnail b{position:absolute;right:14px;bottom:14px;width:32px;height:32px;display:grid;place-items:center;border:1px solid #4b8998;border-radius:50%;background:var(--color-surface)}.simulation-card>div:last-child{padding:20px}.simulation-card small{color:var(--color-muted);font:10px var(--font-mono);letter-spacing:.08em}.simulation-card h3{margin:7px 0}.simulation-card p{font-size:13px}.resource-note{margin-top:14px}
.subject-choice-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px}.subject-choice{display:flex;align-items:center;gap:14px;border:1px solid var(--color-border);border-radius:var(--radius-md);padding:18px;background:var(--color-surface);min-width:0;transition:border-color var(--motion-fast),background var(--motion-fast)}.subject-choice>span{color:var(--subject-accent);display:flex}.subject-choice>div{flex:1}.subject-choice>svg{color:var(--color-muted);flex-shrink:0}.subject-choice h3{font-size:15px}.subject-choice p{font-size:11px;margin-top:5px}.subject-coming{border-style:dashed}.subject-coming:hover{border-color:var(--color-border);background:var(--color-surface)}
[data-subject=math]{--subject-accent:var(--color-math)}[data-subject=chemistry]{--subject-accent:var(--color-chemistry)}[data-subject=computing]{--subject-accent:var(--color-computing)}[data-subject=biology]{--subject-accent:var(--color-biology)}
/* Learn: first screen is a topic-finding workspace, not a second hero. */
.learning-platform{max-width:none}.learning-catalog-header{display:flex;align-items:center;justify-content:space-between;gap:24px;margin:0 0 28px}.learning-catalog-header h1{font-size:36px;letter-spacing:-.035em}.learning-catalog-header p{margin-top:10px;font-size:var(--text-sm)}.learning-catalog-header .kicker{color:var(--subject-accent);margin-bottom:6px}.learning-hero-actions{display:flex;align-items:center;gap:10px;flex-wrap:wrap;margin:0;max-width:48%}.learning-hero-actions .primary{max-width:340px;text-align:left}
.learning-stage-tabs{display:grid;grid-template-columns:repeat(5,1fr);gap:4px;padding:5px;margin:0 0 24px;border:1px solid var(--color-border);border-radius:var(--radius-md);background:var(--color-surface);overflow:visible}.learning-stage-tabs button{display:flex;flex-direction:column;align-items:center;justify-content:center;gap:3px;min-height:61px;border:1px solid transparent;border-radius:var(--radius-sm);padding:10px 8px;background:none;color:var(--color-muted);font:600 14px var(--font-ui);white-space:nowrap}.learning-stage-tabs button small{font:10px var(--font-mono);color:inherit;opacity:1}.learning-stage-tabs button:hover{background:var(--color-raised);color:var(--color-text)}.learning-stage-tabs button[aria-pressed=true]{background:#173749;color:var(--color-primary);border-color:#3a7585;box-shadow:none}
.learning-catalog{padding:0;border:0;background:none}.learning-catalog-tools{display:grid;grid-template-columns:minmax(160px,1fr) 180px 180px;gap:14px;align-items:end;padding:0;margin:0 0 20px;background:none;border:0}.learning-catalog-tools label{display:grid;gap:7px;font-size:12px;color:var(--color-muted)}.learning-catalog-tools input,.learning-catalog-tools select{width:100%;font-size:14px;min-height:46px;border-color:var(--color-control-border)}.learning-catalog-progress{display:flex;gap:18px;align-items:center;margin-bottom:20px;font-size:12px;color:var(--color-muted)}.learning-catalog-progress progress{max-width:160px}.learning-catalog #learning-count{font:12px var(--font-mono);margin:0 0 14px;color:var(--color-muted)}
.learning-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}.learning-card{border:1px solid var(--color-border);border-radius:var(--radius-md);background:var(--color-surface);box-shadow:none;overflow:hidden;min-width:0;transition:background var(--motion-fast),border-color var(--motion-fast);transform:none}.learning-card:hover{background:var(--color-raised);border-color:var(--subject-accent);transform:none;box-shadow:none;color:var(--color-text)}.learning-card-band{padding:15px 20px 0;display:flex;justify-content:space-between;gap:10px;min-height:0;background:none!important;color:var(--color-muted);font:10px var(--font-mono);text-transform:uppercase;letter-spacing:.03em;border:0}.learning-card-band>span:last-child{font-size:10px;font-weight:400;color:var(--color-muted);opacity:1}.learning-card-body{padding:16px 20px 20px}.learning-topic-icon{display:grid;place-items:center;width:36px;height:36px;border-radius:var(--radius-sm);background:var(--color-raised);color:var(--subject-accent);margin-bottom:14px;font:23px var(--font-mono)}.learning-card h2{font-size:19px;line-height:1.3;letter-spacing:-.025em;margin:0 0 10px;min-height:2.6em}.learning-card-body>p{color:var(--color-muted);font-size:13px;line-height:1.6;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden;margin:0;min-height:3.2em}.learning-card-status{display:flex;gap:8px;align-items:center;margin:16px 0 0;color:var(--color-muted);font-size:11px}.learning-content-tags{display:flex;flex-wrap:wrap;gap:5px;margin-top:14px}.learning-content-tags span{border:1px solid var(--color-border);border-radius:4px;padding:3px 6px;font-size:10px;color:var(--color-muted);line-height:1.4}.learning-card-bottom{display:flex;align-items:center;justify-content:space-between;gap:10px;padding-top:15px;margin-top:16px;border-top:1px solid var(--color-border);font-size:11px;color:var(--color-muted)}.learning-card-bottom b{font-size:19px;color:var(--subject-accent)}.learning-topic-card progress{display:block;margin-top:12px}.learning-scope{margin:28px 0 0;padding:12px 20px;border:1px solid var(--color-border);border-radius:var(--radius-md);background:var(--color-surface)}.learning-scope summary{font-size:14px;font-weight:600}.learning-scope p{font-size:13px;margin:12px 0}.learning-scope .learning-inline-links{flex-wrap:wrap}.learning-empty{padding:36px;border:1px dashed var(--color-border);border-radius:var(--radius-md);background:var(--color-surface)}
/* A lesson is a readable document with optional investigations loaded on demand. */
.unit-breadcrumb{font-size:12px;margin-bottom:18px;display:flex;gap:9px;flex-wrap:wrap;color:var(--color-muted)}.unit-breadcrumb a{min-height:24px;color:var(--color-muted)}.unit-breadcrumb a:hover{color:var(--color-primary)}
.unit-hero{padding:0 0 28px;margin:0 0 28px;display:flex;justify-content:space-between;align-items:start;gap:24px;border:0;border-bottom:1px solid var(--color-border);border-radius:0;background:none!important}.unit-hero h1{font-size:clamp(26px,3.5vw,38px);max-width:800px}.unit-hero p{max-width:740px;font-size:14px;margin-top:14px}.unit-hero .kicker{font-size:10px;color:var(--subject-accent)}.unit-hero-actions{display:flex;flex-wrap:wrap;gap:8px;flex-shrink:0;max-width:230px;margin:0}.unit-hero-actions .quiet{font-size:12px;padding:10px 12px}
.unit-layout{display:grid;grid-template-columns:235px minmax(0,1fr);gap:30px;align-items:start}.unit-sidebar{position:sticky;top:20px;padding:0;background:none;border:0;overflow:visible;display:block;max-height:calc(100vh - 40px);overflow-y:auto}.unit-stage-outline{border:0;padding:0}.unit-stage-outline summary{font:600 12px var(--font-ui);padding:12px;border-bottom:1px solid var(--color-border)}.unit-sidebar nav{display:flex;flex-direction:column;gap:3px;margin:12px 0}.unit-sidebar nav a{display:flex;gap:10px;align-items:start;min-height:44px;padding:10px 12px;background:none;border:1px solid transparent;border-radius:var(--radius-sm);font-size:12px;line-height:1.5;color:var(--color-muted);white-space:normal;min-width:0;max-width:none}.unit-sidebar nav a span{font:11px/1.7 var(--font-mono);color:var(--color-muted);width:20px;flex-shrink:0}.unit-sidebar nav a[aria-current=page]{border-color:#376574;background:#15303d;color:var(--color-primary)}.unit-sidebar nav a:hover{background:var(--color-raised);color:var(--color-text)}.unit-sidebar .quiet{margin:8px 12px;font-size:12px}.unit-main{min-width:0}.unit-tabs{display:flex;gap:4px;margin:0 0 20px;padding:4px;background:var(--color-surface);border:1px solid var(--color-border);border-radius:var(--radius-md);overflow:auto;scrollbar-width:thin}.unit-tabs a{padding:11px 14px;min-height:44px;flex:1;white-space:nowrap;text-align:center;font-size:12px;color:var(--color-muted);border:1px solid transparent;border-radius:var(--radius-sm);background:none}.unit-tabs a[aria-current=page]{background:var(--color-raised);color:var(--color-text);border-color:var(--color-border);box-shadow:none}.unit-tabs a:hover{color:var(--color-primary)}
.unit-section,.unit-notes{padding:26px;margin:0 0 20px;border:1px solid var(--color-border);border-radius:var(--radius-md);background:var(--color-surface);box-shadow:none}.unit-section h2{font-size:23px;line-height:1.35;margin:0 0 18px;max-width:65ch}.unit-section h3{font-size:17px;line-height:1.4;margin:18px 0 10px}.unit-section p{font-size:15px;max-width:72ch;margin:12px 0;line-height:1.8}.unit-section ul,.unit-section ol{font-size:14px;color:var(--color-muted);line-height:1.85;padding-left:23px}.unit-section summary{font-size:14px;color:var(--color-primary)}.lesson-overview{padding:18px 24px}.lesson-overview h2{font-size:18px;margin-bottom:6px}.lesson-overview>p{font-size:13px;margin:6px 0}.lesson-overview .kicker{font-size:10px;margin-bottom:6px}.lesson-flow{display:flex;flex-wrap:wrap;gap:8px 22px;list-style:decimal;padding-left:18px;font-size:11px!important;margin-bottom:0}.unit-objectives{padding:0;margin:0 0 22px;border:0;background:none}.unit-objectives h3,.unit-objectives h2{font-size:18px}.unit-objectives ul{padding-left:20px}.unit-depth article h3{font-size:20px}.depth-map{padding:16px;background:var(--color-bg)}.unit-equations{display:grid;gap:12px}.unit-equations>div{padding:18px;background:var(--color-bg);border:1px solid var(--color-border);border-radius:var(--radius-sm);overflow-x:auto}.unit-equations strong{font:18px var(--font-mono);color:var(--color-primary);white-space:normal}.unit-equations p{margin:10px 0 0;font-size:12px}.unit-example{padding:20px;margin-top:20px;border:1px solid #315b69;border-radius:var(--radius-sm);background:#102630}.unit-example h3{margin:8px 0;font-size:17px}.unit-pitfall{background:var(--color-bg);border:0;border-left:3px solid var(--color-warning);padding:16px 18px;margin-top:20px}.unit-pitfall strong{color:var(--color-warning);font-size:13px}.unit-pitfall p{font-size:13px;margin:8px 0 0}.lesson-summary{border-left:3px solid var(--color-success)}
.unit-answer{display:flex;align-items:start;gap:12px;min-height:48px;border:1px solid var(--color-control-border);background:var(--color-bg);border-radius:var(--radius-sm);padding:13px 14px;margin:8px 0;font-size:14px;line-height:1.6;color:var(--color-text);cursor:pointer}.unit-answer input{margin-top:3px}.unit-answer:has(input:checked){border-color:var(--color-primary);background:#143341}.unit-answer:hover{background:var(--color-raised)}#unit-quiz fieldset{border:0;border-top:1px solid var(--color-border);padding:20px 0 8px;margin:20px 0 0;min-width:0}#unit-quiz legend{font-size:15px;color:var(--color-text);line-height:1.6;font-weight:600;padding-right:10px}#unit-quiz fieldset p{font-size:13px}#unit-quiz-result{color:var(--color-primary)}
.unit-understood{padding:22px;margin:24px 0;border:1px solid #366559;border-radius:var(--radius-md);background:#102a28}.unit-understood h2{font-size:20px}.unit-understood p{font-size:13px;margin:10px 0}.unit-understood>a{font-size:13px;color:var(--color-success)}.unit-notes h2{font-size:20px;margin-bottom:14px}.unit-notes textarea{display:block;width:100%;margin:10px 0 14px;min-height:120px}.unit-notes p{font-size:12px;margin-top:12px}.unit-notes label{font-size:13px}.unit-nextbar{position:sticky;bottom:12px;z-index:15;display:flex;justify-content:space-between;gap:10px;align-items:center;padding:12px;margin-top:26px;border:1px solid var(--color-control-border);border-radius:var(--radius-md);background:var(--color-surface);box-shadow:var(--shadow-lg)}.unit-nextbar a{font-size:12px;min-width:0;text-align:center}.unit-nextbar .primary{flex:1}.unit-nextbar>a:last-child:not(.primary){max-width:130px}
.learning-inline-links{display:flex;flex-wrap:wrap;gap:10px}.unit-resource-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px}.unit-resource{padding:20px;border:1px solid var(--color-border);border-radius:var(--radius-md);background:var(--color-bg)}.unit-resource h3{margin-top:0}.unit-resource p{font-size:13px}.unit-resource .primary,.unit-resource .quiet{margin:6px 4px 0 0;font-size:12px}.unit-exam-list article{border:1px solid var(--color-border);background:var(--color-bg);padding:20px;border-radius:var(--radius-md)}.unit-exam-list h3{margin-top:0}.study-viewer{background:var(--color-surface);border-color:var(--color-control-border);color:var(--color-text)}.study-viewer button{min-height:44px}.study-viewer iframe{min-height:0}.study-sharing{display:flex;align-items:start;gap:12px}.study-sharing input{margin-top:4px}.study-table{font-size:12px}.stage-stat-grid article{background:var(--color-surface);border-color:var(--color-border)}
/* Equations always retain readable source text until the optional renderer loads. */
.katex-display{margin:12px 0;overflow-x:auto;overflow-y:hidden;padding-block:5px}.katex{font-size:1.1em}.equation-rendered{font-family:inherit}.unit-equations [data-equation]{display:block;min-height:1.5em;overflow-x:auto}
.startup-screen{max-width:var(--page-width);min-height:0;margin:auto;padding:48px 24px;background:none}.startup-screen h1{max-width:640px}.startup-screen p{margin:18px 0}.startup-screen .primary{margin-right:12px}.startup-screen nav{display:flex;flex-wrap:wrap;gap:12px}.startup-screen .startup-links a{min-height:44px;display:inline-flex;align-items:center;color:var(--color-primary)}#startup-status{font-size:13px}.startup-shell{padding:16px 24px;border-bottom:1px solid var(--color-border)}
/* Only user-triggered hover and short page transitions. Simulation animations
   are controlled separately by their explicit playback buttons. */
.star-drift,.cloud-drift,.planet-system,.orbiter,.signal-dot,.instrument-light{animation:none!important}.research-hero .observatory-scene{transform:none!important}
::view-transition-old(root),::view-transition-new(root){animation-duration:var(--motion-page)}
@media(min-width:1100px){.shell-language{display:block}.shell-language select{max-width:105px;font-size:12px;min-height:44px}.shell-language label>span{display:none}.topbar{gap:18px}.shell-account span{display:inline}}
@media(max-width:1000px){.topbar{gap:14px}.topbar nav a{padding:10px 9px}.home-hero{gap:28px}.path-card{padding:18px;gap:10px}.path-card>svg{display:none}.unit-layout{grid-template-columns:200px minmax(0,1fr);gap:20px}.learning-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.subject-choice-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.unit-hero-actions{max-width:180px}.unit-hero-actions .quiet{width:100%}}
@media(max-width:900px){
 html{scroll-padding-top:20px}body{padding-bottom:calc(72px + env(safe-area-inset-bottom))}.topbar{padding:12px 20px;gap:12px;min-height:68px}.topbar .desktop-nav{display:none}.brand{font-size:21px}.subject-switch{max-width:155px}.subject-switch select{font-size:12px;border-color:var(--color-control-border)}.shell-account{display:none}.mobile-nav{position:fixed;inset:auto 0 0;display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:0;z-index:50;padding:6px 8px calc(6px + env(safe-area-inset-bottom));background:var(--color-bg);border-top:1px solid var(--color-control-border)}.mobile-nav a{display:flex;flex-direction:column;align-items:center;justify-content:center;gap:4px;min-height:54px;padding:6px 2px;font-size:10px;color:var(--color-muted);border-radius:var(--radius-sm)}.mobile-nav a[aria-current=page]{background:var(--color-raised);color:var(--color-primary)}.mobile-nav svg{width:20px;height:20px}
 main#page-content{padding:28px 20px 40px}.learning-home{gap:32px}.home-hero{grid-template-columns:1fr;padding:10px 0 0;gap:24px}.home-hero h1{font-size:clamp(30px,7vw,46px);max-width:540px}.home-hero p{font-size:15px;margin:18px 0 22px}.hero-model{display:none}.home-hero .primary{width:100%;max-width:380px}.home-hero small{font-size:11px}.section-heading{align-items:start}.section-heading h2{font-size:22px}.section-heading .eyebrow{font-size:9px}.section-heading .text-link{font-size:12px;flex-shrink:0}.path-grid{grid-template-columns:1fr;gap:10px}.path-card{padding:18px;align-items:center}.path-card>svg{display:block}.path-card h3{font-size:18px;margin:2px 0 4px}.path-card p{font-size:12px}.path-number{font-size:16px;margin-right:6px}.path-card small{font-size:10px}.home-continue{flex-wrap:wrap;gap:14px;padding:20px}.home-continue .continue-icon{width:42px;height:42px}.home-continue>div:nth-child(2){min-width:190px}.home-continue h2{font-size:18px}.home-continue .primary{width:100%}.simulation-grid{grid-template-columns:1fr;gap:12px}.simulation-card{display:grid;grid-template-columns:110px minmax(0,1fr)}.simulation-thumbnail{height:100%;min-height:130px;flex-direction:column;gap:10px;border:0;border-right:1px solid var(--color-border)}.simulation-thumbnail>svg{width:26px;height:26px}.simulation-thumbnail>span{font-size:15px}.simulation-thumbnail b{display:none}.simulation-card>div:last-child{padding:16px}.simulation-card h3{font-size:17px}.simulation-card p{font-size:12px}.simulation-card small{font-size:9px}.subject-choice-grid{grid-template-columns:1fr}.subject-choice{padding:16px}.site-footer{grid-template-columns:1fr;padding:28px 20px}.site-footer nav{gap:0 18px}.site-footer small{font-size:11px}
 .learning-catalog-header{align-items:start;margin-bottom:22px;gap:14px}.learning-catalog-header h1{font-size:30px}.learning-catalog-header p{font-size:13px}.learning-catalog-header .learning-hero-actions{display:none}.learning-stage-tabs{grid-template-columns:repeat(4,minmax(0,1fr));gap:2px;padding:4px;position:relative;margin-bottom:20px}.learning-stage-tabs button{font-size:12px;min-height:58px;padding:8px 3px;white-space:normal}.learning-stage-tabs button small{font-size:9px}.learning-stage-tabs button[data-learning-stage=all]{grid-column:1/-1;min-height:34px;display:block;font-size:11px;border-radius:4px}.learning-catalog-tools{grid-template-columns:1fr 1fr;gap:12px}.learning-catalog-tools label:first-child{grid-column:1/-1}.learning-catalog-tools label{font-size:11px}.learning-catalog-tools input,.learning-catalog-tools select{font-size:14px}.learning-catalog-progress{font-size:11px;gap:12px}.learning-catalog-progress progress{max-width:90px}.learning-grid{gap:12px}.learning-card-band{padding:14px 16px 0;font-size:9px}.learning-card-band>span:last-child{font-size:9px}.learning-card-body{padding:14px 16px 16px}.learning-card h2{font-size:18px;min-height:0}.learning-card-body>p{font-size:13px}.learning-card-status{font-size:10px}.learning-topic-icon{width:30px;height:30px;margin-bottom:12px}.learning-content-tags{gap:4px}.learning-content-tags span{font-size:9px}.learning-card-bottom{font-size:10px}
 .unit-hero{flex-direction:column;margin-bottom:18px;padding-bottom:20px;gap:16px}.unit-hero h1{font-size:28px}.unit-hero p{font-size:14px;margin-top:12px}.unit-hero-actions{max-width:none;flex-wrap:nowrap;gap:8px}.unit-hero-actions .quiet{width:auto;font-size:11px;min-height:44px}.unit-layout{display:flex;flex-direction:column;gap:16px}.unit-sidebar{position:static;width:100%;max-height:none;overflow:visible;background:var(--color-surface);border:1px solid var(--color-border);border-radius:var(--radius-md);padding:0}.unit-stage-outline summary{padding:14px 16px;border-bottom:0;min-height:48px}.unit-sidebar nav{margin:0 8px 8px;max-height:300px;overflow-y:auto}.unit-sidebar nav a{width:auto}.unit-main{width:100%}.unit-tabs{margin-bottom:16px;gap:2px;border-radius:8px}.unit-tabs a{font-size:11px;padding:11px 12px;flex:0 0 auto}.unit-section,.unit-notes{padding:20px 18px;margin-bottom:16px}.unit-section h2{font-size:21px}.unit-section p{font-size:14px;line-height:1.8}.unit-section ul,.unit-section ol{font-size:13px}.lesson-overview{padding:16px 18px}.lesson-overview h2{font-size:17px}.lesson-flow{display:block;font-size:12px!important}.unit-example{padding:16px}.unit-equations>div{padding:14px}.unit-equations strong{font-size:16px}.unit-objectives{margin-bottom:18px}.unit-nextbar{bottom:calc(78px + env(safe-area-inset-bottom));padding:8px;gap:8px}.unit-nextbar a{font-size:11px;padding:10px;min-height:44px}.unit-nextbar>a:last-child:not(.primary){display:none}.unit-nextbar .primary{max-width:none}.unit-resource-grid{grid-template-columns:1fr}.unit-exam-list article{display:block;padding:16px}.exam-resource-actions{margin-top:16px}.unit-understood{padding:18px}.unit-understood h2{font-size:19px}.unit-breadcrumb{font-size:11px;gap:7px}.stage-stat-grid{grid-template-columns:repeat(2,minmax(0,1fr))}
}
@media(max-width:600px){.learning-grid{grid-template-columns:1fr}.learning-card h2{font-size:19px}.learning-topic-card .learning-card-body{position:relative;padding-left:64px}.learning-topic-icon{position:absolute;left:16px;top:14px}.learning-card-band{padding-left:64px}.learning-card-bottom{font-size:11px}.learning-content-tags span{font-size:10px}.learning-catalog-progress{align-items:start;flex-direction:column;gap:8px}.learning-catalog-progress progress{max-width:none}.learning-scope{padding:10px 16px}.topbar{padding-inline:16px}.subject-switch{max-width:150px}main#page-content{padding-inline:16px}.unit-hero h1{font-size:27px}.section-heading .text-link{font-size:11px}.section-heading h2{font-size:21px}.home-continue>div:nth-child(2){min-width:0}.home-continue .continue-icon{display:none}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*::before,*::after{scroll-behavior:auto!important;animation-duration:.01ms!important;animation-iteration-count:1!important;transition-duration:.01ms!important}.hero-model{transform:none}::view-transition-old(root),::view-transition-new(root){animation:none!important}}
@media print{.topbar,.mobile-nav,.site-footer,.unit-sidebar,.unit-tabs,.unit-nextbar,.unit-hero-actions{display:none!important}body{background:white;color:black;padding:0}main#page-content{padding:0;max-width:none}.unit-layout{display:block}.unit-section{break-inside:avoid;background:white;color:black;border-color:#bbb}h1,h2,h3,p{color:black!important}}

.learning-card-progress{margin-top:14px;font:11px/1.5 var(--font-mono);color:var(--color-muted)}.learning-card-progress progress{margin:8px 0 0}.account-required .topbar{padding:14px 20px;background:var(--color-bg);border-bottom:1px solid var(--color-border)}

.startup-screen .startup-links a.primary{color:var(--color-on-primary)}

/* subject-scenes.css */
/* Subject color carries through the catalog and lesson, without moving behind text. */
main[data-subject=chemistry]{--subject-accent:var(--color-chemistry);--scene-tint:#15362e}main[data-subject=math]{--subject-accent:var(--color-math);--scene-tint:#29213d}main[data-subject=computing]{--subject-accent:var(--color-computing);--scene-tint:#142d48}main[data-subject=biology]{--subject-accent:var(--color-biology);--scene-tint:#263620}main[data-subject=physics]{--subject-accent:var(--color-physics);--scene-tint:#123241}
main#page-content{position:relative;isolation:isolate}.subject-atmosphere{position:absolute;inset:0 0 auto;height:470px;overflow:hidden;pointer-events:none;z-index:-1;background:radial-gradient(ellipse at 90% 12%,var(--scene-tint,#123241),transparent 65%)}.subject-atmosphere span{position:absolute;left:calc(7% + var(--particle)*19%);top:calc(35px + var(--particle)*47px);font:clamp(18px,3vw,36px) var(--font-mono);color:var(--subject-accent,#63d8e8);opacity:.12;transform:rotate(-12deg)}
.subject-scene{--scene-accent:#63d8e8;position:relative;overflow:hidden;border:1px solid var(--color-control-border);background:linear-gradient(135deg,#102435,#091421);border-radius:20px;padding:22px;margin:0 0 28px;box-shadow:0 12px 40px #0002}.subject-scene[data-scene=chemistry]{--scene-accent:#80dfbd;background:linear-gradient(135deg,#12312e,#091923)}.subject-scene[data-scene=math]{--scene-accent:#b9a2ff;background:linear-gradient(135deg,#231e38,#101827)}.subject-scene[data-scene=computing]{--scene-accent:#8fbaff;background:linear-gradient(135deg,#142b45,#0b1627)}.subject-scene[data-scene=biology]{--scene-accent:#c1de84;background:linear-gradient(135deg,#213322,#0c1923)}
.scene-subjects{display:flex;gap:6px;flex-wrap:wrap;margin-bottom:22px}.scene-subjects button{background:transparent;color:var(--color-muted);border:1px solid transparent;padding:8px 12px;border-radius:8px;min-height:44px;font-size:12px}.scene-subjects button[aria-pressed=true]{color:var(--color-text);background:#ffffff10;border-color:var(--scene-accent)}.scene-heading{display:flex;align-items:center;justify-content:space-between;gap:16px}.scene-heading h2{font-size:20px;line-height:1.4;max-width:34ch}.scene-heading .eyebrow{font-size:10px;color:var(--scene-accent)}.scene-play{flex-shrink:0;font-size:12px}.scene-art{max-width:620px;margin:0 auto}.scene-art svg{display:block;width:100%;height:auto;max-height:280px}.scene-readout{display:flex;gap:22px;justify-content:center;flex-wrap:wrap;border-block:1px solid #ffffff20;padding:12px 0;font:12px var(--font-mono);color:var(--color-muted)}.scene-readout b{color:var(--scene-accent);font-size:16px;margin-left:6px}.scene-inputs{display:flex;gap:20px;margin-top:16px}.scene-inputs label{flex:1;min-width:0;color:var(--color-muted);font-size:12px}.scene-inputs input{display:block;width:100%;min-height:40px;accent-color:var(--scene-accent);padding:0;background:transparent}.scene-note,.scene-detail{font-size:12px!important;line-height:1.6!important;color:var(--color-muted);margin:12px 0 0!important}.scene-detail{font-family:var(--font-mono)}.scene-enter{display:inline-flex;min-height:44px;align-items:center;color:var(--scene-accent);margin-top:12px}.home-explorer{margin-top:-12px}.scene-compact{max-width:780px;margin:0 0 26px}.scene-compact .scene-art svg{max-height:180px}.subject-lesson-mark{border-left:3px solid var(--subject-accent);padding:8px 14px;background:var(--scene-tint);font:12px var(--font-mono);color:var(--subject-accent);margin:0 0 18px}.lesson-language-note{font-size:12px;color:var(--color-muted);padding:10px 14px;border:1px solid var(--color-border);border-radius:8px;margin-bottom:18px}
.learning-home .home-hero{grid-template-columns:1fr;max-width:800px;padding-bottom:0}.home-hero h1{max-width:760px}.catalog-scene{margin:0 0 20px}.catalog-scene>summary{cursor:pointer;min-height:44px;display:list-item;padding:12px 0;color:var(--subject-accent);font-size:13px}.catalog-scene[open]>.subject-scene{margin-top:12px}.subject-atmosphere span{animation:subject-arrival 8s ease-out both}.subject-atmosphere span:nth-child(even){animation-duration:10s}@keyframes subject-arrival{from{opacity:0;transform:translateY(20px) rotate(-18deg)}to{opacity:.12;transform:translateY(0) rotate(-12deg)}}
.shell-language{display:block!important}.shell-language select{max-width:115px}.entry-subject-links{display:flex;gap:8px;flex-wrap:wrap;margin-top:20px}.entry-subject-links a{font-size:12px;border:1px solid var(--color-border);padding:8px 12px;border-radius:8px;min-height:44px;display:flex;align-items:center}
@media(max-width:900px){.topbar{flex-wrap:wrap}.shell-language{margin-left:auto}.shell-language .language-picker{display:flex}.shell-language select{max-width:108px}.subject-switch{margin-left:auto}.subject-scene{padding:18px 14px}.scene-heading h2{font-size:17px}.scene-heading{align-items:flex-start}.scene-play{font-size:11px;padding:8px 10px}.scene-subjects{gap:4px;margin-bottom:16px}.scene-subjects button{font-size:11px;padding:8px}.scene-readout{gap:10px 18px;justify-content:flex-start}.scene-readout b{font-size:14px}.scene-inputs{gap:12px}.scene-compact .scene-art svg{max-height:200px}.subject-atmosphere{height:330px}}
@media(max-width:420px){.topbar{gap:8px}.topbar .brand{font-size:19px}.subject-switch{max-width:135px}.shell-language{width:100%;display:flex!important;justify-content:flex-end}.shell-language select{min-height:36px}.scene-heading{flex-wrap:wrap;gap:10px}.scene-play{min-height:44px}.scene-inputs{flex-wrap:wrap}.scene-inputs label{flex:1 1 42%}.scene-note{font-size:11px!important}}
@media(prefers-reduced-motion:reduce){.subject-scene *,.subject-atmosphere span{animation:none!important;transition:none!important}}