:root{color-scheme:light;--paper:#f5f7ef;--ink:#203c3a;--teal:#126c64;--line:#d5ded1;--gold:#e9bd55;--muted:#536963}*{box-sizing:border-box}body{margin:0;background:var(--paper);color:var(--ink);font:16px/1.6 system-ui,-apple-system,"Segoe UI",sans-serif}[hidden]{display:none!important}button,input,select,textarea{font:inherit}button,a,input,select,textarea{touch-action:manipulation}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible,textarea:focus-visible,summary:focus-visible{outline:3px solid #b78618;outline-offset:3px}a{color:var(--teal)}.lab-shell{max-width:1280px;margin:0 auto;padding:28px 24px 32px}.eyebrow{font-size:11px;font-weight:800;letter-spacing:.13em;margin:0 0 8px;color:var(--teal)}h1{font-size:clamp(29px,3vw,44px);font-weight:800;line-height:1.12;letter-spacing:-.035em;max-width:780px;margin:0 0 15px}h2{font-size:23px;font-weight:750;letter-spacing:-.02em;margin:0 0 12px;line-height:1.2}h3{font-size:18px;font-weight:750}.lead-text{max-width:900px;font-size:18px;margin-bottom:18px}.exercise{background:#fff4d6;border-left:4px solid var(--gold);padding:14px 18px;border-radius:0 14px 14px 0;margin-bottom:24px}.exercise code{color:#365148}.lab-layout{display:grid;grid-template-columns:310px minmax(0,1fr);gap:22px;align-items:start}.lab-card{background:#fff;border:1px solid var(--line);border-radius:20px;padding:22px;min-width:0;box-shadow:0 6px 20px #274c4205}.controls{padding:22px 20px}.section-heading{display:flex;justify-content:space-between;align-items:start;gap:12px}.section-heading>div{min-width:0}.jump{display:inline-flex;min-height:44px;align-items:center;font-size:13px;font-weight:750;white-space:nowrap;text-underline-offset:3px}.controls .section-heading{display:block}.controls .jump{display:none}label{display:block;font-weight:650;font-size:14px;margin:14px 0 6px}.form-select{min-height:46px;border-color:#becdc2;font-size:14px;color:var(--ink);background-color:#fff;border-radius:10px;padding-right:30px}.hint{font-size:12px;line-height:1.55;color:var(--muted);margin:8px 0 13px}.range-heading{display:flex;justify-content:space-between;gap:14px;align-items:center}.range-heading label{margin:9px 0 0;min-width:0}.range-heading output{font:700 13px ui-monospace,monospace;white-space:nowrap;margin-top:9px}.form-range{min-height:44px;height:44px;margin:0;accent-color:var(--teal)}.form-range::-webkit-slider-thumb{background:var(--teal)}.form-range::-moz-range-thumb{background:var(--teal)}fieldset{padding:0;border:0;margin:10px 0}legend{float:none;width:auto;font-size:14px;font-weight:800;margin-bottom:5px}.check{display:flex;align-items:center;gap:10px;min-height:44px;margin:0;font-weight:450;font-size:13px}.check input{width:20px;height:20px;accent-color:var(--teal);flex:0 0 auto}.anchor-fields{border-top:1px solid var(--line);margin-top:18px;padding-top:18px}.btn{min-height:44px;border-radius:10px;font-weight:700;white-space:normal;font-size:14px;padding:10px 15px}.btn-primary{background:var(--teal);border-color:var(--teal)}.btn-primary:hover{background:#0d564f;border-color:#0d564f}.btn-outline-primary{color:var(--teal);border-color:var(--teal)}.btn-outline-primary:hover{background:var(--teal);border-color:var(--teal)}.btn-outline-secondary{border-color:#b4c3b8;color:#36554e}.preview{min-width:0;position:sticky;top:12px}.scene-card{padding:20px}.presets{display:flex;flex-wrap:wrap;gap:7px;margin:4px 0 14px}.presets button{min-height:44px;border:1px solid #c4d0c6;background:#f8faf5;color:var(--ink);border-radius:10px;padding:7px 11px;font-size:12px;font-weight:650}.presets button:hover{background:#e5efdf}.stage{position:relative;width:100%;height:420px;overflow:hidden;border:1px solid #afc3b6;border-radius:15px;background-color:#edf3e7;background-image:linear-gradient(#bfd0bf55 1px,transparent 1px),linear-gradient(90deg,#bfd0bf55 1px,transparent 1px);background-size:24px 24px;isolation:isolate}.stage-label{position:absolute;right:12px;bottom:8px;color:#71816b;font-size:10px;letter-spacing:.08em;text-transform:uppercase;pointer-events:none}.anchor{position:absolute;min-height:48px;border:2px solid #0e5c54;border-radius:12px;background:var(--teal);color:#fff;font-size:13px;font-weight:750;padding:10px 14px;white-space:nowrap;z-index:2;box-shadow:0 4px 0 #0d4f4830}.floating-panel{position:absolute;left:0;top:0;max-width:calc(100% - 16px);width:240px;background:#fffdf6;border:1px solid #d2b565;border-radius:13px;box-shadow:0 10px 22px #24433822;color:#263d37;z-index:3}.floating-content{padding:15px 16px;position:relative;z-index:1;border-radius:12px;background:#fffdf6}.floating-content strong{font-size:14px;display:block;line-height:1.35;margin-bottom:7px}.floating-content p{font-size:12px;line-height:1.5;margin:0 0 9px}.panel-chip{display:inline-block;font:10px ui-monospace,monospace;padding:5px 7px;border-radius:6px;background:#f3e6c1;max-width:100%;overflow-wrap:anywhere}.floating-arrow{width:10px;height:10px;background:#fffdf6;transform:rotate(45deg);border:1px solid #d2b565;z-index:0}.metrics{display:grid;grid-template-columns:1fr 1fr 1.2fr;gap:10px;margin-top:16px}.metrics>div{min-width:0;padding:9px 10px;background:#f1f5eb;border-radius:10px}.metrics span{font-size:11px;color:var(--muted);display:block}.metrics output{font:700 13px ui-monospace,monospace;overflow-wrap:anywhere}.result-note{font-size:13px;line-height:1.55;margin:14px 0;color:#3b554b}.preview-actions,.source-actions{display:flex;flex-wrap:wrap;gap:8px}.learning-note{padding:20px 3px 0;font-size:13px;color:#3c554d}.learning-note p{margin:8px 0}.learning-note code{color:#265a51}.source-card{margin-top:24px}.source-card>p{max-width:950px}.source-card .form-select{max-width:430px}textarea{display:block;width:100%;resize:vertical;min-height:190px;background:#173b36;color:#e9f5dc;border:0;border-radius:12px;padding:16px;font:13px/1.65 ui-monospace,SFMono-Regular,Consolas,monospace;tab-size:2;margin:12px 0 14px;white-space:pre;overflow:auto}#lab-html-source{min-height:200px}.status{margin:12px 0 0;font-size:14px;font-weight:600;min-height:24px}summary{cursor:pointer;font-weight:700;min-height:44px;padding:10px 0}details{border-top:1px solid var(--line);margin-top:15px;padding-top:5px}.alert-note{padding:16px;background:#fff0e8;border:1px solid #e3bda8;border-radius:12px}.source-card code{color:var(--teal)}@media(max-width:900px){.lab-layout{grid-template-columns:270px minmax(0,1fr);gap:14px}.lab-shell{padding:20px 16px}.lab-card{padding:18px}.scene-card .section-heading{display:block}.scene-card .jump{display:none}.metrics{grid-template-columns:1fr 1fr}.metrics>div:last-child{grid-column:1/-1}.stage{height:420px}.presets button{font-size:12px}.form-select{font-size:16px}}@media(max-width:700px){.lab-shell{padding:18px 12px 24px}.lab-layout{display:flex;flex-direction:column;gap:18px}.preview{order:-1;position:static;width:100%}.controls{width:100%}.scene-card{padding:15px}.scene-card .section-heading{display:flex;flex-wrap:wrap}.scene-card .jump,.controls .jump{display:inline-flex}.controls .section-heading{display:flex;align-items:center}.exercise{font-size:14px;padding:12px 14px}.lead-text{font-size:16px}.lab-header h1{font-size:30px}.stage{border-radius:12px}.presets{gap:6px}.presets button{flex:1 1 calc(50% - 6px);font-size:13px}.presets button:last-child{flex-basis:100%}.metrics{grid-template-columns:1fr 1fr}.metrics output{font-size:13px}.learning-note{padding:18px 4px 0}.form-select,textarea{font-size:16px}.controls label,legend{font-size:15px}.hint{font-size:13px}.check{font-size:14px;min-height:48px}.source-actions .btn{flex:1 1 100%}.preview-actions .btn{flex:1 1 140px}textarea{padding:13px}.source-card{padding:18px}.floating-content{padding:13px}.floating-content strong{font-size:14px}.floating-content p{font-size:12px}}
@media(max-width:700px){.floating-content p{font-size:14px}.panel-chip{font-size:11px}}