:root{--paper:#f4f2eb;--card:#fffcf6;--ink:#193c45;--muted:#53666b;--line:#d9dfd7;--teal:#215f5b;--accent:#d9ec9d;--orange:#a94f27;--radius:24px;--shadow:0 12px 35px #203c4110;--base:17px}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:var(--paper);color:var(--ink);font-family:"Avenir Next","Nunito Sans",ui-rounded,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;font-size:var(--base);line-height:1.55}button,input,select,textarea{font:inherit;color:inherit}button,a,input,select,textarea{-webkit-tap-highlight-color:transparent}button{cursor:pointer;touch-action:manipulation;border:0}button:disabled{cursor:default;opacity:.55}button{min-height:46px}button:focus-visible,a:focus-visible,summary:focus-visible{outline:3px solid #b44c1e;outline-offset:4px}input:focus,textarea:focus,select:focus{outline:3px solid #478d84;outline-offset:2px}a{color:var(--teal)}svg{display:block;max-width:100%}h1,h2,h3,p{margin:0}h1{font-size:clamp(32px,4vw,53px);line-height:1.1;letter-spacing:-1.8px;font-weight:650}h2{font-size:26px;line-height:1.2;letter-spacing:-.65px;font-weight:650}h3{font-size:19px;line-height:1.3;font-weight:650}p{color:var(--muted)}.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap}.skip-link{position:fixed;top:-100px;z-index:100;background:var(--ink);color:white;padding:15px}.skip-link:focus{top:8px}.shell{max-width:1400px;margin:auto;min-height:100dvh;display:grid;grid-template-columns:216px minmax(0,1fr)}.sidebar{position:sticky;top:0;height:100dvh;border-right:1px solid var(--line);padding:35px 24px 22px;display:flex;flex-direction:column;gap:35px}.brand{display:flex;gap:13px;align-items:center;text-align:left;background:none;padding:0;color:var(--ink);min-height:52px}.brand img{height:43px;width:43px;border-radius:13px}.brand b{font-size:28px;letter-spacing:-1.5px;font-weight:680;line-height:1}.brand small{display:block;font-size:11px;font-weight:650;letter-spacing:3px;margin-top:6px;text-transform:uppercase}.nav-list{display:grid;gap:8px}.nav-item{padding:12px 14px;display:flex;align-items:center;gap:12px;border-radius:13px;background:none;font-size:14px;font-weight:600;text-align:left;min-height:51px}.nav-item.active{background:var(--ink);color:var(--card)}.nav-item:not(.active):hover{background:#e9ece1}.icon{width:22px;height:22px;display:inline-block;flex-shrink:0;vertical-align:middle}.sidebar-bottom{margin-top:auto;display:grid;gap:6px}.sidebar-note{font-size:12px;line-height:1.7;color:var(--muted);padding:10px 14px}.main-area{min-width:0;padding:0 42px 40px}.topbar{display:flex;align-items:center;justify-content:space-between;gap:15px;min-height:100px}.eyebrow{font-size:11px;letter-spacing:1.8px;text-transform:uppercase;font-weight:750;color:var(--muted)}.topbar-actions{display:flex;align-items:center;gap:10px}.icon-btn{height:44px;min-width:44px;padding:9px;border-radius:50%;background:transparent;display:inline-flex;align-items:center;justify-content:center}.icon-btn:hover{background:#e4e8dd}.profile-btn{display:flex;align-items:center;gap:9px;border:1px solid var(--line);background:var(--card);border-radius:28px;padding:6px 13px 6px 6px;font-size:13px;font-weight:650}.avatar{width:33px;height:33px;border-radius:50%;background:#e4eecb;display:inline-flex;align-items:center;justify-content:center;font-size:20px}.welcome{display:flex;align-items:end;justify-content:space-between;gap:16px;margin:11px 0 26px}.welcome p{font-size:15px;margin-top:10px}.quiet-chip{display:inline-flex;align-items:center;gap:7px;border:1px solid var(--line);border-radius:24px;padding:7px 12px;font-size:12px;white-space:nowrap}.hero{display:grid;grid-template-columns:1.1fr 1fr;min-height:285px;border-radius:var(--radius);background:#193f43;color:#f8f9ec;overflow:hidden;position:relative;box-shadow:var(--shadow)}.hero-copy{padding:34px 0 30px 34px;z-index:1}.hero .eyebrow{color:#cee2c5;letter-spacing:2px}.hero h2{font-size:clamp(30px,3vw,40px);font-weight:550;letter-spacing:-1.2px;margin:14px 0}.hero p{color:#d7e4dc;font-size:15px;max-width:345px}.hero-art{display:grid;align-items:center;position:relative;overflow:hidden}.hero-art svg{width:100%;height:100%;object-fit:contain;max-height:300px}.button{display:inline-flex;align-items:center;justify-content:center;gap:10px;border-radius:13px;padding:13px 20px;font-weight:650;font-size:15px;text-decoration:none;border:1px solid transparent;min-height:49px;background:var(--ink);color:var(--card);transition:transform .16s,background .16s}.button:hover{transform:translateY(-1px);background:#285961}.button.lime{background:var(--accent);color:#183b37}.button.lime:hover{background:#e5f4b9}.button.secondary{background:var(--card);border-color:var(--line);color:var(--ink)}.button.secondary:hover{background:#edf0e6}.button.outline{background:transparent;border-color:#89a29b;color:inherit}.button.small{font-size:13px;padding:9px 14px;min-height:42px}.button.full{width:100%}.button.danger{background:#8d3c2e;color:#fff}.hero .button{margin-top:22px;min-width:158px}.hero-footer{font-size:11px;color:#bdd2c7;margin-top:11px}.section-top{display:flex;align-items:center;justify-content:space-between;gap:14px;margin:31px 0 15px}.section-top h2{font-size:22px}.link-btn{display:inline-flex;align-items:center;gap:7px;background:none;font-size:13px;font-weight:650;padding:7px 0;min-height:40px;color:var(--teal)}.quick-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}.quick-card{background:var(--card);border:1px solid var(--line);border-radius:19px;padding:22px;text-align:left;display:flex;flex-direction:column;align-items:flex-start;position:relative;min-height:192px;transition:transform .17s,box-shadow .17s}.quick-card:hover,.topic-card:hover,.mission-card:hover{transform:translateY(-3px);box-shadow:var(--shadow)}.tile-icon{height:43px;width:43px;border-radius:13px;display:grid;place-items:center;background:#e3ebd2;margin-bottom:15px}.tile-icon .icon{width:25px;height:25px}.quick-card h3{font-size:17px}.quick-card p{font-size:13px;margin-top:7px}.quick-card .arrow{position:absolute;top:25px;right:20px}.bottom-panel{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin-top:24px}.progress-panel,.note-panel{border:1px solid var(--line);border-radius:18px;padding:20px;display:flex;align-items:center;gap:18px;background:transparent}.progress-ring{width:66px;height:66px;flex-shrink:0}.progress-panel h3,.note-panel h3{font-size:15px}.progress-panel p,.note-panel p{font-size:12px;margin-top:5px}.note-panel{background:#e9ede0;border-color:#e0e5d7}.note-panel>.icon{width:34px;height:34px}.page-intro{margin:12px 0 25px}.page-intro p{margin-top:12px;font-size:15px;max-width:630px}.topic-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px}.topic-card{border:1px solid var(--line);background:var(--card);border-radius:19px;padding:23px;text-align:left;display:flex;align-items:center;gap:17px;transition:transform .17s,box-shadow .17s}.topic-card .tile-icon{margin:0;width:53px;height:53px;flex-shrink:0}.topic-card h3{font-size:17px}.topic-card p{font-size:12px;margin-top:5px}.topic-card .arrow{margin-left:auto}.search{display:flex;align-items:center;gap:12px;background:var(--card);border:1px solid var(--line);padding:8px 15px;border-radius:13px;margin-bottom:20px}.search input{background:none;border:0;min-width:0;width:100%;padding:6px;font-size:16px;outline:none}.skill-list{display:grid;gap:10px}.skill-row{background:var(--card);border:1px solid var(--line);border-radius:15px;padding:16px 19px;display:flex;align-items:center;gap:16px;text-align:left}.skill-row h3{font-size:16px}.skill-row p{font-size:12px;margin-top:4px}.skill-row .skill-number{font-size:12px;color:var(--muted);width:22px}.skill-row .row-action{margin-left:auto;font-size:12px;font-weight:700;white-space:nowrap;display:flex;align-items:center;gap:10px}.small-dots{display:flex;gap:4px}.small-dots i{height:5px;width:5px;border-radius:50%;background:#c8d3cb}.small-dots i.lit{background:var(--teal)}.back{margin-bottom:12px}.mission-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:18px}.mission-card{padding:25px;border:1px solid var(--line);background:var(--card);border-radius:23px;text-align:left;transition:transform .17s}.mission-art{height:115px;border-radius:14px;display:grid;place-items:center;margin-bottom:18px}.mission-art .icon{height:70px;width:70px;stroke-width:1}.mission-card p{margin-top:7px;font-size:14px}.mission-card small{display:block;margin-top:17px;font-size:12px;font-weight:650}.paper-grid{display:grid;gap:14px}.paper-card{border:1px solid var(--line);border-radius:20px;padding:25px;background:var(--card);display:flex;align-items:center;gap:20px}.paper-card h3{font-size:22px}.paper-card p{font-size:13px;margin-top:7px}.paper-card .button{margin-left:auto}.paper-num{font-size:32px;line-height:1;width:66px;height:75px;display:grid;place-items:center;background:#e5ecd9;border-radius:16px}.info-box{background:#e8eddf;padding:20px 23px;border-radius:16px;font-size:14px;margin-top:24px}.info-box p+p{margin-top:10px}.collection-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:17px}.collection-card{border:1px solid var(--line);background:var(--card);border-radius:20px;padding:15px}.collection-card svg{height:160px;width:100%}.collection-card h3{font-size:15px;margin-top:10px}.collection-card p{font-size:12px;margin-top:5px}.collection-card.locked{opacity:.6}.pill-row{display:flex;flex-wrap:wrap;gap:9px}.pill{background:var(--card);border:1px solid var(--line);border-radius:30px;padding:9px 14px;font-size:13px}.pill.selected{background:var(--ink);color:var(--card)}
/* The learning canvas */
.player{max-width:1280px;margin:auto;padding:20px 30px 50px}.player-top{display:flex;align-items:center;justify-content:space-between;gap:16px;margin-bottom:21px}.player-brand{display:flex;align-items:center;gap:13px}.player-brand span{font-size:13px}.player-top .actions{display:flex;align-items:center;gap:6px}.progress-track{height:5px;background:#dde3d7;border-radius:10px;overflow:hidden;margin:0 0 24px}.progress-track div{height:100%;background:var(--teal);transition:width .3s}.player-heading{display:flex;justify-content:space-between;align-items:center;margin-bottom:15px;gap:12px}.player-heading .eyebrow{font-size:11px}.question-layout{display:grid;grid-template-columns:minmax(0,1.7fr) minmax(275px,1fr);gap:23px;align-items:start}.question-card{background:var(--card);border:1px solid var(--line);border-radius:25px;padding:30px;min-width:0;box-shadow:var(--shadow)}.question-card h1{font-size:clamp(23px,2.3vw,31px);line-height:1.4;font-weight:570;letter-spacing:-.6px;max-width:760px;overflow-wrap:anywhere}.question-expression{font-size:clamp(27px,4.2vw,48px);font-weight:600;line-height:1.55;text-align:center;padding:22px 4px 8px;font-variant-numeric:tabular-nums;overflow-wrap:anywhere}.frac{display:inline-flex;flex-direction:column;text-align:center;vertical-align:middle;line-height:1.05;font-size:.76em;margin:0 .12em;transform:translateY(-.02em)}.frac>span:first-child{padding:0 .14em .09em;border-bottom:1.5px solid currentColor}.frac>span:last-child{padding:.1em .14em 0}.model{margin:22px 0 0;background:#f6f7f0;border:1px solid #e0e6d8;border-radius:17px;padding:16px 12px;overflow:hidden}.model svg{width:100%;max-height:360px}.model figcaption{color:var(--muted);font-size:12px;text-align:center;padding:7px 9px 0;line-height:1.5}.model-table-wrap{overflow:auto;padding:6px}.model-table{border-collapse:collapse;width:100%;font-size:15px;font-variant-numeric:tabular-nums}.model-table th,.model-table td{padding:13px 10px;text-align:center;border-bottom:1px solid var(--line)}.model-table thead th{background:#e6ecdf;font-size:13px}.model-table tbody th{font-weight:600}.data-table{font-size:12px;padding:8px}.data-table summary{cursor:pointer;min-height:35px;display:flex;align-items:center}.support-bar{display:flex;flex-wrap:wrap;gap:8px;border-top:1px solid var(--line);padding-top:18px;margin-top:25px}.support-btn{display:flex;align-items:center;gap:7px;background:#edf0e5;border:1px solid #dce3d2;padding:10px 12px;border-radius:12px;font-size:12px;font-weight:600;min-height:44px}.support-btn.selected{background:var(--teal);color:white;border-color:var(--teal)}.support-btn .icon{width:17px;height:17px}.hint-box{background:#f0e9d9;border-left:3px solid var(--orange);padding:16px 17px;margin-top:18px;border-radius:0 12px 12px 0;font-size:15px;color:var(--ink)}.answer-panel{background:var(--card);border:1px solid var(--line);border-radius:23px;padding:25px;position:sticky;top:20px}.answer-panel h2{font-size:18px;margin-bottom:14px}.answer-panel label{display:block;font-size:13px;margin-bottom:6px;color:var(--muted)}.answer-input-wrap{display:flex;align-items:center;gap:10px}.answer-input{width:100%;min-width:0;border:1.5px solid #a7b9ae;border-radius:13px;background:#fffef9;font-size:28px;text-align:center;padding:14px 10px;height:69px;font-variant-numeric:tabular-nums}.answer-input-wrap .unit{font-size:21px;font-weight:600;white-space:nowrap}.pair-inputs{display:grid;grid-template-columns:1fr 1fr;gap:11px}.input-help{font-size:11px;line-height:1.5;margin:9px 0 17px;color:var(--muted)}.answer-panel .button.full{margin-top:14px}.choice-list{display:grid;gap:10px}.choice{background:#fffef9;border:1.5px solid #cbd6c9;border-radius:12px;padding:13px 15px;display:flex;align-items:center;gap:12px;text-align:left;font-size:16px;line-height:1.5;min-height:55px;overflow-wrap:anywhere}.choice .choice-dot{width:20px;height:20px;border:1.5px solid #9cac9b;border-radius:50%;flex-shrink:0;display:grid;place-items:center;font-size:11px}.choice.selected{background:#e3edd4;border-color:var(--teal)}.choice.selected .choice-dot{border:5px solid var(--teal);background:#f2f6dc}.order-preview{min-height:57px;padding:12px;background:#edf2e3;border:1px dashed #adbea6;border-radius:13px;font-size:18px;line-height:1.7;margin-bottom:10px}.reason-box{margin-top:20px;border-top:1px solid var(--line);padding-top:18px}.reason-box h3{font-size:15px;font-weight:650;margin-bottom:10px}.reason-box .choice{font-size:13px;padding:10px 12px;min-height:49px}.feedback{margin-top:17px;background:#e1ecd7;border-radius:13px;padding:15px;font-size:14px;line-height:1.6}.feedback.retry{background:#f2e7d6}.feedback strong{display:block;font-size:16px;margin-bottom:5px}.feedback p{font-size:13px}.feedback.error{background:#f1dfd8}.support-pane{margin-top:20px;padding:23px;border:1px solid #cedcca;background:#edf2e4;border-radius:18px}.support-pane h2{font-size:21px;margin:4px 0 13px}.support-pane p{font-size:15px}.step-count{font-size:10px;letter-spacing:1.4px;text-transform:uppercase;color:var(--muted);font-weight:700}.step-expression{font-size:25px;margin:15px 0;font-weight:600;line-height:1.5}.step-answer{display:flex;gap:9px}.step-answer input{width:130px;max-width:100%;border:1px solid #a7b9ae;border-radius:11px;padding:10px;font-size:21px;background:#fffef8}.step-feedback{font-size:13px;padding:10px 0;color:var(--teal)}.step-history{font-size:12px;color:var(--muted);margin-bottom:14px;line-height:1.8}.example-label{font-size:12px;padding:10px;background:#e4ead8;border-radius:10px;margin-bottom:15px}.scratch{margin-top:17px}.scratch summary{min-height:45px;cursor:pointer;font-size:13px;display:flex;align-items:center;gap:8px;color:var(--teal);font-weight:600}.scratch-area{padding-top:8px}.scratch canvas{display:block;width:100%;height:230px;background-color:#fffef9;background-image:radial-gradient(#d2d9d0 1px,transparent 1px);background-size:20px 20px;border:1px solid var(--line);border-radius:13px;touch-action:none}.scratch textarea,.workings{width:100%;min-height:95px;border:1px solid #bbc8b7;border-radius:12px;padding:12px;background:#fffef9;font-size:15px;resize:vertical}.scratch-tools{display:flex;gap:10px;align-items:center}.quiet-row{display:flex;justify-content:space-between;align-items:center;gap:10px;margin-top:15px}.quiet-row .link-btn{font-size:12px}.keypad{display:grid;grid-template-columns:repeat(3,1fr);gap:7px;margin:14px 0}.keypad button{border:1px solid var(--line);border-radius:10px;background:#f0f3e9;font-size:21px;min-height:49px}.explain-box{font-size:14px;line-height:1.8;background:#f0ebda;padding:18px;border-radius:15px;margin-top:18px}.explain-box summary{font-weight:650;cursor:pointer;min-height:32px}.explain-box p{margin-top:8px}.paper-nav{display:flex;flex-wrap:wrap;gap:7px;margin:18px 0}.paper-nav button{border:1px solid var(--line);background:var(--card);border-radius:9px;min-width:40px;min-height:40px;font-size:12px;position:relative}.paper-nav button.current{background:var(--ink);color:white}.paper-nav button.answered{box-shadow:inset 0 -4px 0 #4d8977}.paper-nav button.flagged:after{content:"";width:6px;height:6px;position:absolute;right:4px;top:4px;border-radius:50%;background:var(--orange)}.paper-clock{font-variant-numeric:tabular-nums;font-size:14px;font-weight:650;padding:8px 12px;border:1px solid var(--line);border-radius:22px}.paper-banner{font-size:12px;color:var(--muted);margin-bottom:15px}.result-hero{padding:35px;text-align:center;background:#e5eddb;border-radius:24px}.result-hero h1{font-size:38px}.result-hero p{margin-top:12px}.result-stats{display:flex;justify-content:center;gap:40px;margin:24px 0}.result-stats b{display:block;font-size:31px;font-weight:550}.result-stats span{font-size:12px;color:var(--muted)}.review-row{border:1px solid var(--line);border-radius:16px;padding:18px;background:var(--card);margin-top:12px}.review-row h3{font-size:16px}.review-row p{font-size:13px;margin-top:7px}.review-row details{font-size:13px;margin-top:10px}.review-row summary{cursor:pointer;min-height:34px}.review-row .model{max-width:650px}.summary-actions{display:flex;flex-wrap:wrap;justify-content:center;gap:10px;margin-top:23px}.empty{padding:45px 22px;text-align:center;border:1px dashed #aebfac;border-radius:20px}.empty p{margin:10px 0 19px}.teacher-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:16px}.teacher-card{border:1px solid var(--line);border-radius:19px;padding:24px;background:var(--card)}.teacher-card p{font-size:13px;margin:12px 0}.teacher-card h3{font-size:18px}.teacher-table{width:100%;border-collapse:collapse;font-size:12px}.teacher-table th,.teacher-table td{padding:11px;text-align:left;border-bottom:1px solid var(--line)}.teacher-table th{background:#e8eede}.table-scroll{overflow:auto}.badge{font-size:11px;font-weight:600;display:inline-flex;align-items:center;gap:5px;padding:5px 9px;border-radius:20px;background:#e5edda}.source-list{padding-left:20px;font-size:13px}.source-list li{margin:13px 0}.source-list a{overflow-wrap:anywhere}.teacher-sources p{margin:10px 0;font-size:13px}
dialog{border:1px solid #ced9c7;border-radius:24px;background:var(--card);color:var(--ink);padding:28px;width:min(94vw,580px);max-height:90dvh;box-shadow:0 30px 100px #132c4366}dialog::backdrop{background:#142b3a70;backdrop-filter:blur(4px)}.dialog-heading{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-bottom:18px}.dialog-heading h2{font-size:25px}.dialog-body p{font-size:14px;margin:10px 0 17px}.setting-row{display:flex;justify-content:space-between;align-items:center;gap:20px;padding:15px 0;border-bottom:1px solid var(--line)}.setting-row strong{font-size:14px;font-weight:650}.setting-row small{font-size:12px;color:var(--muted);display:block;margin-top:4px}.toggle{height:30px;width:51px;min-height:30px;flex-shrink:0;position:relative;background:#b4c0b0;border-radius:25px}.toggle:after{content:"";position:absolute;height:24px;width:24px;border-radius:50%;left:3px;top:3px;background:#fffef9;transition:transform .2s}.toggle[aria-checked=true]{background:var(--teal)}.toggle[aria-checked=true]:after{transform:translateX(21px)}.profile-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}.profile-choice{border:1px solid var(--line);border-radius:14px;background:#f4f5ed;padding:14px 9px;text-align:center}.profile-choice .avatar{margin:auto auto 8px}.profile-choice span:last-child{display:block;font-size:13px;overflow-wrap:anywhere}.profile-choice.selected{border:2px solid var(--teal);background:#e4eed8}.form-label{display:block;font-size:13px;margin:15px 0 6px}.text-input,select{border:1px solid #b5c2af;border-radius:11px;background:#fffef8;padding:11px 12px;width:100%;font-size:16px}.dialog-actions{display:flex;gap:10px;flex-wrap:wrap;margin-top:22px;justify-content:flex-end}.field-row{display:grid;grid-template-columns:1fr 1fr;gap:12px}#toast{position:fixed;bottom:24px;left:50%;transform:translate(-50%,20px);background:var(--ink);color:var(--card);box-shadow:var(--shadow);border-radius:15px;padding:13px 20px;max-width:90vw;opacity:0;pointer-events:none;z-index:99;font-size:14px;transition:opacity .2s,transform .2s}#toast.show{opacity:1;transform:translate(-50%,0)}.focus-mode .sidebar,.focus-mode .topbar{display:none}.focus-mode .shell{grid-template-columns:1fr}.focus-mode .main-area{max-width:1100px;margin:auto;padding-top:25px}.high-contrast{--paper:#fffdf4;--card:#ffffff;--muted:#253f43;--line:#86968b;--ink:#102f34}.large-text{--base:20px}.large-text .question-card h1{font-size:34px}.large-text .choice{font-size:19px}.large-text .model figcaption{font-size:15px}.large-text .support-btn{font-size:15px}.reading-space{letter-spacing:.035em;word-spacing:.08em}.reading-space .question-card h1{line-height:1.65}.reduced-motion *, .reduced-motion *:before,.reduced-motion *:after{animation:none!important;transition:none!important;scroll-behavior:auto!important}
@media(prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important;scroll-behavior:auto!important}}
@media(min-width:1450px){.shell{max-width:1500px;grid-template-columns:236px 1fr}.main-area{padding-left:55px;padding-right:55px}.hero{min-height:320px}.hero-copy{padding:40px}.hero-art svg{max-height:330px}}
@media(max-width:1100px){.shell{grid-template-columns:174px 1fr}.sidebar{padding:26px 15px;gap:26px}.brand b{font-size:25px}.brand img{width:38px;height:38px}.nav-item{padding:11px 12px;font-size:13px;gap:9px}.main-area{padding:0 27px 35px}.hero-copy{padding:28px 0 25px 27px}.hero{grid-template-columns:1.1fr .85fr}.hero-art svg{min-width:230px}.quick-card{padding:18px}.bottom-panel{gap:12px}.progress-panel,.note-panel{padding:17px;gap:13px}.question-layout{grid-template-columns:minmax(0,1.4fr) minmax(270px,1fr)}.question-card{padding:24px}.player{padding:19px 22px 35px}.answer-panel{padding:21px}}
@media(max-width:820px){.shell{display:block;padding-bottom:79px}.sidebar{height:auto;position:fixed;top:auto;bottom:0;z-index:20;display:block;padding:0;background:#fbfaf3f5;backdrop-filter:blur(15px);width:100%;border-right:0;border-top:1px solid var(--line)}.sidebar>.brand,.sidebar-bottom{display:none}.nav-list{display:flex;justify-content:space-around;padding:7px 10px max(9px,env(safe-area-inset-bottom))}.nav-item{display:flex;flex-direction:column;gap:3px;min-width:64px;min-height:50px;padding:5px 9px;font-size:10px;border-radius:12px}.nav-item .icon{height:20px;width:20px}.main-area{padding:0 25px 24px}.topbar{min-height:80px}.topbar .eyebrow{display:none}.topbar:before{content:"six · maths";font-size:25px;font-weight:650;letter-spacing:-1px}.hero{min-height:275px}.welcome h1{font-size:38px}.welcome p{font-size:14px}.quick-card{min-height:178px}.quick-card p{font-size:12px}.quick-card h3{font-size:15px}.bottom-panel{grid-template-columns:1fr 1fr}.question-layout{grid-template-columns:minmax(0,1.3fr) minmax(250px,1fr);gap:17px}.question-card{padding:22px}.answer-panel{padding:18px}.support-btn{font-size:11px;padding:9px}.question-card h1{font-size:24px}.player{padding:15px 18px 30px}.player-brand .brand b{font-size:23px}.player-brand .brand small{display:none}.player-brand .brand img{width:33px;height:33px}.teacher-grid{grid-template-columns:1fr}.paper-card{padding:20px}.paper-card h3{font-size:20px}.paper-card .button{font-size:13px;padding:10px 14px}}
@media(max-width:650px){.main-area{padding:0 18px 25px}.topbar{min-height:75px}.topbar-actions{gap:1px}.profile-btn{font-size:11px;padding-right:10px}.profile-btn .avatar{width:29px;height:29px;font-size:17px}.topbar-actions>.icon-btn{width:39px;min-width:39px}.welcome{align-items:start;margin:9px 0 21px}.welcome h1{font-size:35px;letter-spacing:-1.1px}.welcome .quiet-chip{display:none}.hero{grid-template-columns:1fr .64fr;min-height:284px}.hero-copy{padding:27px 0 25px 23px}.hero h2{font-size:31px}.hero p{font-size:13px}.hero-art{margin-left:-32px;opacity:.85}.hero-art svg{min-width:235px;height:240px}.hero .button{min-width:130px;padding:11px 16px;margin-top:20px;font-size:14px}.hero-footer{font-size:10px;max-width:220px}.hero .eyebrow{font-size:9px}.quick-grid{grid-template-columns:1fr;gap:10px}.quick-card{min-height:98px;display:grid;grid-template-columns:44px 1fr;grid-template-rows:auto auto;column-gap:16px;padding:18px}.quick-card .tile-icon{grid-row:1/3;margin:0}.quick-card h3{font-size:16px;padding-right:20px}.quick-card p{font-size:12px;margin-top:4px;max-width:270px;padding-right:20px}.quick-card .arrow{top:36px;right:16px}.section-top{margin:25px 0 13px}.section-top h2{font-size:20px}.bottom-panel{grid-template-columns:1fr}.note-panel{display:none}.topic-grid{grid-template-columns:1fr;gap:10px}.topic-card{padding:17px}.topic-card h3{font-size:16px}.topic-card .tile-icon{width:46px;height:46px}.mission-grid{grid-template-columns:1fr}.mission-card{padding:20px}.mission-art{height:105px}.collection-grid{grid-template-columns:repeat(2,1fr);gap:12px}.collection-card svg{height:130px}.paper-card{display:grid;grid-template-columns:48px 1fr;gap:14px}.paper-card .paper-num{width:48px;height:59px;font-size:26px}.paper-card .button{grid-column:2;margin:0;justify-self:start}.paper-card h3{font-size:19px}.page-intro h1{font-size:35px}.question-layout{display:block}.player{padding:13px 14px 35px}.player-top{margin-bottom:16px;gap:10px}.player-brand>span{font-size:11px;max-width:130px}.player-brand{gap:9px}.player-top .actions{gap:0}.player-top .icon-btn{min-width:40px;padding:8px}.player-brand .brand b{display:none}.player-brand .brand img{width:32px;height:32px}.player-top .button.small{padding:7px 10px;font-size:11px;min-height:40px}.progress-track{margin-bottom:18px}.question-card{padding:22px 19px;border-radius:20px}.question-card h1{font-size:24px;line-height:1.45}.question-expression{font-size:34px;padding-top:16px}.model{padding:12px 7px;margin-top:18px;border-radius:13px}.model svg{max-height:370px}.model figcaption{font-size:11px}.support-bar{gap:6px;padding-top:15px;margin-top:20px}.support-btn{font-size:11px;padding:9px 10px}.support-btn .icon{width:15px;height:15px}.answer-panel{margin-top:15px;position:static;padding:22px;border-radius:20px}.answer-input{height:61px;font-size:28px}.answer-panel h2{font-size:17px;margin-bottom:11px}.input-help{margin-bottom:12px}.answer-panel .button.full{min-height:51px}.answer-panel .choice{font-size:16px}.answer-panel .reason-box .choice{font-size:13px}.paper-nav{gap:5px}.paper-nav button{min-width:35px;min-height:36px}.support-pane{padding:18px}.result-hero{padding:25px 16px}.result-hero h1{font-size:31px}.result-stats{gap:23px}.result-stats b{font-size:27px}.result-stats span{font-size:10px}.result-hero p{font-size:14px}.quiet-row{flex-wrap:wrap}.step-expression{font-size:23px}.step-answer{flex-wrap:wrap}.step-answer input{width:120px}.teacher-table{min-width:650px}.profile-grid{grid-template-columns:repeat(2,1fr)}dialog{padding:22px}.field-row{grid-template-columns:1fr}.large-text .question-card h1{font-size:28px}.large-text .choice{font-size:20px}}
@media print{.sidebar,.topbar,.player-top,.support-bar,.answer-panel,.button,.paper-nav,.quiet-row,.summary-actions,#toast{display:none!important}.shell,.question-layout{display:block}.main-area,.player{padding:0}.question-card,.review-row{box-shadow:none;break-inside:avoid;border:1px solid #ddd}.model{break-inside:avoid}.review-row details{display:block}.review-row details>*{display:block}body{background:white;font-size:12pt}.model svg{max-height:220px}}
.lab-banner{margin:0 0 22px;padding:21px 23px;border:1px solid #c8d7c0;border-radius:19px;background:#e8efdc;display:flex;justify-content:space-between;align-items:center;gap:18px}.lab-banner h3{font-size:18px}.lab-banner p{font-size:13px;margin-top:5px}.lab-layout{display:grid;grid-template-columns:1.6fr 1fr;gap:23px;align-items:start}.lab-layout .model{margin-top:0}.lab-stats{display:flex;justify-content:space-around;gap:15px;margin-top:20px;flex-wrap:wrap}.lab-stat{text-align:center}.lab-stat span{display:block;font-size:12px;color:var(--muted)}.lab-stat b{font-size:25px;font-weight:550;display:block;margin-top:7px}.lab-control{padding:11px 0 18px;border-bottom:1px solid var(--line);margin-bottom:13px}.lab-control>span{font-size:13px;display:block;margin-bottom:10px}.lab-stepper{display:flex;align-items:center;gap:20px}.lab-stepper button{width:44px;height:44px;background:#e7efdc;border:1px solid #b8c9ae;border-radius:13px;font-size:26px}.lab-stepper output{font-size:25px;min-width:28px;text-align:center}
@media(max-width:820px){.lab-layout{grid-template-columns:1.3fr 1fr;gap:16px}}
@media(max-width:650px){.lab-layout{display:block}.lab-banner{display:block}.lab-banner .button{margin-top:14px}.lab-stat b{font-size:21px}}
.model-expand{font-size:11px;margin:3px auto 0;display:flex;justify-content:center;min-height:34px;padding:5px 10px}
dialog.model-dialog{width:min(96vw,1200px);max-height:96dvh}.expanded-model svg{width:100%;height:min(68dvh,650px);max-height:68dvh}.expanded-model figcaption{text-align:center;font-size:14px}.expanded-model .data-table{font-size:15px}
@media(max-width:900px) and (min-width:651px){.question-layout{grid-template-columns:minmax(0,1.4fr) minmax(250px,1fr)}.model{padding-left:5px;padding-right:5px}}
@media(max-width:650px){.hero{display:block;min-height:295px}.hero-copy{padding:25px 24px;position:relative;width:100%;z-index:1}.hero h2{font-size:30px;max-width:290px;letter-spacing:-.9px}.hero p{max-width:232px}.hero-art{position:absolute;width:155px;height:166px;right:-8px;bottom:10px;margin:0;opacity:.55;pointer-events:none}.hero-art svg{height:165px;min-width:240px;transform:translateX(-34px)}.hero-footer{max-width:240px}.hero .button{margin-top:20px}.player-top .button.small{white-space:nowrap}.player-brand>span{font-size:10px;max-width:106px}.player-top .actions .icon-btn{min-width:35px;width:35px;padding:7px}}

.model-division svg{max-height:750px;height:auto}

@media(max-width:380px){.nav-list .nav-item{min-width:0;flex:1;padding-left:3px;padding-right:3px;font-size:9px}.profile-btn{font-size:0}.player-brand>span{display:none}.topbar:before{font-size:23px}}

.collection-card.locked{opacity:1}.collection-card.locked svg{opacity:.65}