:root{
  --bg:#f6f3ed;--paper:#fffdfa;--panel:#ffffff;--ink:#182033;--muted:#667085;--line:#dfe4ec;
  --blue:#2855d9;--blue-2:#5f7fe8;--blue-soft:#edf2ff;--yellow:#f8c84a;--yellow-soft:#fff7d6;
  --orange:#e9883d;--red:#d65757;--green:#2d8b68;--cyan:#26a6b6;--purple:#7d64ce;
  --shadow:0 16px 45px rgba(31,42,68,.10);--shadow-sm:0 8px 22px rgba(31,42,68,.07);--radius:22px;
}
*{box-sizing:border-box}html{background:var(--bg)}body{margin:0;color:var(--ink);font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;background:radial-gradient(circle at 15% 0,#fff 0,#faf8f3 35%,#f3f1eb 100%);min-height:100vh}button,input,select{font:inherit}button{touch-action:manipulation}.shell{max-width:1540px;margin:0 auto;padding:18px 18px 42px}.back{display:inline-flex;align-items:center;gap:6px;margin:0 0 8px;color:#41506d;font-weight:850;text-decoration:none;padding:8px 10px;border-radius:12px}.back:hover{background:#fff}.hero{display:flex;align-items:flex-end;justify-content:space-between;gap:24px;padding:10px 2px 20px}.eyebrow{font-size:0.6875rem;font-weight:950;letter-spacing:.14em;color:var(--blue);text-transform:uppercase}.hero h1{font-size:clamp(34px,4.4vw,62px);line-height:.98;letter-spacing:-.045em;margin:6px 0 10px}.hero p{max-width:780px;margin:0;color:var(--muted);line-height:1.55;font-size:0.9375rem}.challenge{background:linear-gradient(145deg,#17223a,#283650);color:#fff;border-radius:18px;padding:15px 18px;min-width:235px;box-shadow:0 16px 35px rgba(23,34,58,.20);border:1px solid rgba(255,255,255,.08)}.challenge span,.challenge small{display:block;color:#cbd5e1}.challenge span{font-size:0.625rem;font-weight:900;letter-spacing:.1em;text-transform:uppercase}.challenge strong{display:block;font-size:1.375rem;margin:3px 0}.challenge small{font-size:0.6875rem}.steps{display:grid;grid-template-columns:repeat(4,1fr);gap:8px;margin-bottom:12px}.step{display:flex;align-items:center;gap:10px;border:1px solid var(--line);background:rgba(255,255,255,.75);border-radius:15px;padding:10px 12px;color:var(--muted)}.step b{display:grid;place-items:center;width:30px;height:30px;border-radius:10px;background:#e9edf4;color:#667085;flex:0 0 auto}.step strong,.step small{display:block}.step strong{font-size:0.75rem;color:var(--ink)}.step small{font-size:0.625rem;margin-top:1px}.step.active{background:#fff;border-color:#b7c5ef;box-shadow:var(--shadow-sm)}.step.active b{background:var(--blue);color:#fff}.grid{display:grid;grid-template-columns:310px minmax(520px,1fr) 340px;gap:14px;align-items:start}.panel{background:rgba(255,255,255,.96);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow-sm)}.controls,.results{padding:16px;position:sticky;top:10px}.panel-title{display:flex;gap:10px;align-items:flex-start;margin-bottom:14px}.num{display:grid;place-items:center;width:34px;height:34px;background:var(--blue);color:#fff;border-radius:11px;font-weight:950;flex:0 0 auto}.panel-title h2{font-size:1.1875rem;margin:0;letter-spacing:-.02em}.panel-title p{font-size:0.6875rem;line-height:1.45;color:var(--muted);margin:4px 0 0}.group{margin-top:14px;padding-top:2px}.group:first-of-type{margin-top:0}.group label,.mini{display:block;font-size:0.625rem;text-transform:uppercase;letter-spacing:.08em;color:var(--muted);font-weight:950;margin-bottom:7px}.range-row{display:grid;grid-template-columns:minmax(0,1fr) 82px;gap:9px;align-items:center}.range-row input[type=range]{width:100%;accent-color:var(--blue);height:28px}.value{border:1px solid var(--line);background:#f8fafc;border-radius:11px;padding:8px;text-align:center;font-weight:950;font-size:0.8125rem}.chips{display:grid;grid-template-columns:repeat(3,1fr);gap:7px}.chips:has(.chip:nth-child(4)){grid-template-columns:repeat(2,1fr)}.chip{border:1px solid var(--line);background:#fafbfc;border-radius:13px;padding:10px 7px;min-height:52px;cursor:pointer;text-align:center;color:var(--ink);font-weight:850;transition:.15s ease}.chip:hover{transform:translateY(-1px);border-color:#b9c5dd;background:#fff}.chip small{display:block;color:var(--muted);font-size:0.5625rem;font-weight:700;margin-top:3px}.chip.active{border:2px solid var(--blue);background:var(--blue-soft);padding:9px 6px;box-shadow:inset 0 0 0 2px rgba(40,85,217,.04)}.coach{border:1px solid #cad6f3;background:linear-gradient(145deg,#f7f9ff,#edf2ff);border-radius:14px;padding:12px;margin-top:14px}.coach .mini{color:var(--blue);margin-bottom:4px}.coach strong{display:block;font-size:0.8125rem;line-height:1.38}.coach p{font-size:0.6875rem;line-height:1.48;color:var(--muted);margin:4px 0 0}.test{width:100%;border:0;background:linear-gradient(135deg,#f8c84a,#f1ac31);color:#3b2a00;border-radius:16px;padding:17px;font-size:1.0625rem;font-weight:950;cursor:pointer;margin-top:14px;box-shadow:0 9px 20px rgba(206,147,31,.22);transition:.15s ease}.test:hover{transform:translateY(-1px);box-shadow:0 12px 23px rgba(206,147,31,.28)}.test:active{transform:translateY(1px)}.reset{width:100%;border:1px solid var(--line);background:#fff;border-radius:12px;padding:10px;font-weight:800;color:var(--ink);cursor:pointer;margin-top:8px}.stage-panel{overflow:hidden;border-radius:24px}.stage-top{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:12px 15px;border-bottom:1px solid var(--line);background:#fff}.stage-top strong{font-size:0.8125rem}.stage-top span{font-size:0.625rem;color:var(--muted)}.stage{position:relative;background:linear-gradient(180deg,#f7f9fd 0,#eef2f6 100%);overflow:hidden}.stage:before{content:"";position:absolute;inset:0;background-image:linear-gradient(rgba(40,85,217,.05) 1px,transparent 1px),linear-gradient(90deg,rgba(40,85,217,.05) 1px,transparent 1px);background-size:32px 32px;pointer-events:none}.stage svg{position:relative;display:block;width:100%;height:auto;min-height:430px}.status{display:flex;justify-content:space-between;gap:10px;padding:10px 14px;border-top:1px solid var(--line);background:#fff;color:var(--muted);font-size:0.6875rem}.result-hero{border:1px solid var(--line);background:#f8fafc;border-radius:15px;padding:14px}.result-hero span{display:block;font-size:0.625rem;font-weight:950;letter-spacing:.1em;margin-bottom:4px}.result-hero strong{display:block;font-size:1.1875rem;line-height:1.25}.result-hero p{font-size:0.6875rem;color:var(--muted);line-height:1.5;margin:6px 0 0}.result-hero.good{background:#edf8f3;border-color:#b6dec9}.result-hero.good span{color:var(--green)}.result-hero.warn{background:#fff8e6;border-color:#ecd38c}.result-hero.warn span{color:#a76a00}.result-hero.bad{background:#fff1f1;border-color:#efbdc1}.result-hero.bad span{color:var(--red)}.metrics{display:grid;grid-template-columns:1fr 1fr;gap:8px;margin-top:10px}.metric{border:1px solid var(--line);background:#fafbfc;border-radius:12px;padding:10px}.metric span,.metric small{display:block;color:var(--muted)}.metric span{font-size:0.5625rem}.metric strong{display:block;font-size:1.1875rem;margin:2px 0}.metric small{font-size:0.5625rem}.learn{margin-top:12px;border-top:1px solid var(--line);padding-top:11px}.learn h3{font-size:0.8125rem;margin:0 0 6px}.learn p,.learn li{font-size:0.6875rem;line-height:1.55;color:var(--muted)}.learn ul{padding-left:17px;margin:5px 0}.learning-card{margin-top:12px;border:1px solid #dfe5f1;border-radius:15px;padding:12px;background:linear-gradient(145deg,#fff,#f8faff)}.learning-card .lesson-title{display:flex;align-items:center;gap:8px;font-size:0.8125rem;font-weight:950}.learning-card .lesson-title i{font-style:normal;display:grid;place-items:center;width:30px;height:30px;border-radius:10px;background:var(--blue-soft)}.learning-card p{font-size:0.6875rem;color:var(--muted);line-height:1.5;margin:7px 0 0}.learning-card .try-next{margin-top:8px;padding-top:8px;border-top:1px dashed #cfd7e6;color:#41506d;font-size:0.625rem;font-weight:800}.advanced{margin-top:10px}.advanced summary{cursor:pointer;color:var(--muted);font-size:0.6875rem;font-weight:850}.advanced div{font-size:0.625rem;line-height:1.5;color:var(--muted);padding-top:7px}.hintbar{display:flex;align-items:center;gap:11px;margin-bottom:12px;padding:11px 14px}.hint-icon{display:grid;place-items:center;width:42px;height:42px;border-radius:13px;background:var(--blue-soft);color:var(--blue);font-weight:950;font-size:1.25rem}.hintbar strong{font-size:0.8125rem}.hintbar span{display:block;color:var(--muted);font-size:0.625rem;margin-top:2px}.legend{display:flex;gap:12px;flex-wrap:wrap;padding:8px 13px;border-top:1px solid var(--line);background:#fff;font-size:0.625rem;color:var(--muted)}.legend i{display:inline-block;width:9px;height:9px;border-radius:50%;margin-right:4px}.lab-note{margin-top:12px;padding:14px 16px}.lab-note h2{font-size:1.0625rem;margin:0 0 5px}.lab-note p{font-size:0.6875rem;color:var(--muted);line-height:1.55;margin:0}.pulse{animation:pulse .45s ease}@keyframes pulse{50%{background:#fff7d8}}.shake{animation:shake .34s linear 2}@keyframes shake{0%,100%{transform:translateX(0)}25%{transform:translateX(-4px)}75%{transform:translateX(4px)}}
/* Home */
.home-hero{padding:30px 0 22px}.home-hero-grid{display:grid;grid-template-columns:minmax(0,1fr) 340px;gap:18px;align-items:end}.home-hero h1{font-size:clamp(44px,7vw,82px);margin:8px 0 13px;letter-spacing:-.055em;line-height:.92}.home-hero p{font-size:1.0625rem;max-width:760px;color:var(--muted);line-height:1.55}.brand-mark{display:inline-flex;align-items:center;gap:8px;font-weight:950;letter-spacing:.12em;font-size:0.75rem;color:var(--blue)}.brand-mark i{width:15px;height:15px;background:var(--yellow);border:4px solid var(--blue);border-radius:4px;transform:rotate(12deg)}.home-mission{background:linear-gradient(145deg,#17223a,#2b3b59);color:#fff;border-radius:24px;padding:20px;box-shadow:0 18px 40px rgba(23,34,58,.2)}.home-mission span{font-size:0.625rem;text-transform:uppercase;letter-spacing:.12em;color:#c9d3e6;font-weight:900}.home-mission strong{display:block;font-size:1.75rem;line-height:1.05;margin:6px 0}.home-mission p{font-size:0.6875rem;color:#dbe2ef;margin:0}.section-head{display:flex;align-items:end;justify-content:space-between;gap:16px;margin:12px 0}.section-head h2{margin:0;font-size:1.5rem;letter-spacing:-.03em}.section-head p{margin:0;color:var(--muted);font-size:0.75rem}.home-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px}.lab-card{display:flex;flex-direction:column;text-decoration:none;color:var(--ink);overflow:hidden;transition:.18s ease}.lab-card:hover{transform:translateY(-3px);box-shadow:var(--shadow)}.lab-card .card-scene{height:180px;display:grid;place-items:center;position:relative;overflow:hidden;background:linear-gradient(160deg,#f7f9fe,#eef3fb);border-bottom:1px solid var(--line)}.lab-card .card-scene svg{width:92%;height:92%}.lab-card .card-copy{padding:16px}.lab-card h3{margin:4px 0 7px;font-size:1.375rem;letter-spacing:-.03em}.lab-card p{margin:0;color:var(--muted);font-size:0.75rem;line-height:1.5}.tags{display:flex;flex-wrap:wrap;gap:6px;margin-top:12px}.tag{border:1px solid var(--line);background:#f8fafc;border-radius:999px;padding:5px 8px;font-size:0.5625rem;color:#536075;font-weight:800}.home-note{margin-top:16px;padding:16px 18px}.home-note p{margin:0;font-size:0.75rem;color:var(--muted);line-height:1.55}.home-note strong{color:var(--ink)}
/* visual builder helpers */
.visual-note{position:absolute;top:12px;left:12px;background:rgba(255,255,255,.94);border:1px solid var(--line);padding:8px 10px;border-radius:12px;font-size:0.625rem;color:var(--muted);box-shadow:var(--shadow-sm);z-index:2}.visual-note b{display:block;color:var(--ink);font-size:0.6875rem}.control-readout{display:grid;grid-template-columns:repeat(2,1fr);gap:7px;margin-top:10px}.control-readout div{padding:8px;border-radius:11px;background:#f8fafc;border:1px solid var(--line)}.control-readout span{font-size:0.5625rem;color:var(--muted);display:block}.control-readout strong{font-size:0.75rem;display:block;margin-top:2px}.compare-strip{display:grid;grid-template-columns:1fr auto 1fr;gap:8px;align-items:center;margin-top:10px}.compare-strip>div{border:1px solid var(--line);background:#fafbfc;border-radius:12px;padding:9px}.compare-strip span{display:block;font-size:0.5625rem;color:var(--muted)}.compare-strip strong{font-size:0.75rem}.compare-strip b{color:var(--blue)}
@media(max-width:1100px){.grid{grid-template-columns:280px 1fr}.results{position:static;grid-column:1/-1}.controls{position:static}.home-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.home-hero-grid{grid-template-columns:1fr}.home-mission{max-width:520px}.stage svg{min-height:390px}}
@media(max-width:760px){.shell{padding:12px}.hero{display:block}.challenge{margin-top:14px;min-width:0}.steps{grid-template-columns:1fr 1fr}.grid{grid-template-columns:1fr}.controls,.results{position:static}.stage svg{min-height:330px}.home-grid{grid-template-columns:1fr}.home-hero h1{font-size:3rem}.chips{grid-template-columns:1fr 1fr}.status{display:block}.status span{display:block;margin-top:3px}.home-hero{padding-top:18px}}
/* Gravity Racer component polish */
.racer-grid{grid-template-columns:330px minmax(560px,1fr) 330px}.racer-controls{padding:15px}.racer-mission{display:grid;grid-template-columns:auto minmax(0,1fr) auto}.live-build-badge{border-left:1px solid var(--line);padding-left:14px;text-align:right}.live-build-badge span,.live-build-badge strong{display:block}.live-build-badge span{font-size:0.5625rem;letter-spacing:.08em;font-weight:900;color:var(--muted)}.live-build-badge strong{font-size:0.75rem;margin-top:2px}.build-section{border-top:1px solid var(--line);padding-top:13px;margin-top:13px}.build-section:first-of-type{border-top:0;padding-top:0;margin-top:0}.section-label{display:flex;align-items:center;gap:9px;margin-bottom:8px}.section-label>span{display:grid;place-items:center;width:36px;height:36px;background:#eef2f7;border-radius:11px;font-size:1.0625rem}.section-label b,.section-label small{display:block}.section-label b{font-size:0.8125rem}.section-label small{font-size:0.625rem;color:var(--muted);margin-top:1px}.visual-range .range-row{grid-template-columns:minmax(0,1fr) 76px}.range-hint,.prediction-scale{display:flex;justify-content:space-between;font-size:0.5rem;color:#8a94a4;text-transform:uppercase;letter-spacing:.06em;margin-top:3px}.picture-chips .chip{padding-top:7px}.car-shape{display:block;height:20px;margin:0 auto 6px;background:#e9883d;border:2px solid #4e3924}.car-shape.boxy{width:45px;border-radius:3px}.car-shape.normal{width:46px;border-radius:12px 12px 4px 4px;clip-path:polygon(0 100%,10% 35%,30% 8%,72% 8%,100% 100%)}.car-shape.smooth{width:50px;border-radius:999px 999px 5px 5px;clip-path:polygon(0 100%,14% 45%,38% 15%,76% 20%,100% 100%)}.racer-stage{background:#fbfcfd}.racer-stage svg{min-height:470px}.racer-stage-panel{overflow:hidden}.visual-stats{display:grid;grid-template-columns:repeat(4,1fr);border-top:1px solid var(--line);background:#fff}.visual-stats>div{padding:10px 12px;border-right:1px solid var(--line)}.visual-stats>div:last-child{border-right:0}.visual-stats span,.visual-stats strong{display:block}.visual-stats span{font-size:0.5rem;color:var(--muted);font-weight:900;letter-spacing:.08em}.visual-stats strong{font-size:0.75rem;margin-top:2px}.prediction-box{background:#f8fafc;border:1px solid var(--line);border-radius:14px;padding:12px}.prediction-box label{display:block;font-size:0.75rem;font-weight:850;margin-bottom:7px}.guess-value{font-size:1rem}.racer-test{font-size:1.125rem;min-height:60px}.wheel-group{transform-box:fill-box;transform-origin:center}.wheel-rim{transition:r .15s ease,fill .15s ease}.wheel-tire,.hub,#bodyShape,#windowShape,#weightBlock{transition:all .15s ease}#changeCallout{transition:opacity .18s ease}.track-build{padding-bottom:2px}
@media(max-width:1230px){.racer-grid{grid-template-columns:290px minmax(500px,1fr)}.racer-results{grid-column:1/-1;position:static;display:grid;grid-template-columns:1fr 1fr;gap:9px}.racer-results>.panel-title,.racer-results>.result-hero,.racer-results>.advanced{grid-column:1/-1}}
@media(max-width:820px){.racer-grid{display:block}.racer-controls,.racer-results{position:static;margin-bottom:10px}.racer-stage-panel{margin-bottom:10px}.racer-results{display:block}.racer-mission{grid-template-columns:auto minmax(0,1fr)}.live-build-badge{grid-column:1/-1;border-left:0;border-top:1px solid var(--line);padding:8px 0 0;text-align:left}.racer-stage svg{min-height:350px}.visual-stats{grid-template-columns:1fr 1fr}.visual-stats>div:nth-child(2){border-right:0}.visual-stats>div:nth-child(-n+2){border-bottom:1px solid var(--line)}}

/* v0.7 premium visual system */
:root{
  --bg:#f3f1ec;--paper:#fffdf9;--panel:#fff;--ink:#172033;--muted:#667085;--line:#d9dee8;
  --navy:#17223a;--blue:#315ed8;--blue-soft:#edf3ff;--yellow:#f6c84f;--orange:#ec8b3d;
  --shadow:0 18px 50px rgba(24,32,51,.10);--shadow-sm:0 10px 28px rgba(24,32,51,.08)
}
body{background:linear-gradient(180deg,#faf9f6 0,#f2f0eb 100%);color:var(--ink)}
.panel{border-color:#dce1e9;box-shadow:var(--shadow-sm)}
.back{border:1px solid transparent}.back:hover{border-color:var(--line);background:#fff}
.home-shell{max-width:1500px;padding-top:24px}
.premium-hero{display:grid;grid-template-columns:minmax(0,1fr) minmax(420px,620px);gap:34px;align-items:center;padding:24px 0 34px}
.premium-hero-copy h1{font-size:clamp(54px,7.5vw,96px);line-height:.89;letter-spacing:-.065em;margin:10px 0 18px}.premium-hero-copy h1 span{color:#315ed8}.premium-hero-copy p{max-width:720px;font-size:1.125rem;line-height:1.6;color:#667085;margin:0}.brand-mark{font-size:0.75rem;color:#315ed8}.brand-mark i{background:#f6c84f;border-color:#315ed8}
.hero-flow{display:flex;align-items:center;flex-wrap:wrap;gap:8px;margin-top:24px}.hero-flow span{display:inline-flex;align-items:center;gap:7px;background:#fff;border:1px solid #dbe0e9;border-radius:999px;padding:8px 12px;font-size:0.6875rem;font-weight:900;box-shadow:0 4px 14px rgba(24,32,51,.05)}.hero-flow span b{display:grid;place-items:center;width:22px;height:22px;border-radius:50%;background:#17223a;color:#fff;font-size:0.625rem}.hero-flow i{font-style:normal;color:#9aa4b2;font-weight:900}.hero-workbench{border-radius:34px;overflow:hidden;box-shadow:0 28px 70px rgba(23,34,58,.18);border:1px solid rgba(23,34,58,.08);background:#eef2f8;transform:rotate(.2deg)}.hero-workbench svg{display:block;width:100%;height:auto}
.premium-section-head{margin:20px 0 15px;padding:0 2px}.premium-section-head h2{font-size:1.9375rem;letter-spacing:-.04em}.premium-section-head p{max-width:450px;text-align:right;line-height:1.5}
.premium-grid{grid-template-columns:repeat(3,minmax(0,1fr));gap:18px}.premium-card{border-radius:26px;overflow:hidden;background:#fff;box-shadow:0 12px 34px rgba(24,32,51,.07);border:1px solid #dfe3ea}.premium-card:hover{transform:translateY(-5px);box-shadow:0 24px 54px rgba(24,32,51,.14);border-color:#cbd3df}.premium-card .card-scene{height:224px;border-bottom:0;background:#edf2f8}.premium-card .card-scene:after{content:"";position:absolute;left:18px;right:18px;bottom:0;height:1px;background:rgba(23,32,51,.08)}.premium-card .card-scene svg{width:100%;height:100%}.premium-card .card-copy{padding:19px 19px 18px}.premium-card h3{font-size:1.5625rem;margin:5px 0 8px}.premium-card p{font-size:0.78125rem;line-height:1.58;min-height:58px}.premium-card .eyebrow{font-size:0.625rem}.scene-badge{position:absolute;z-index:3;top:14px;left:14px;background:rgba(255,255,255,.92);border:1px solid rgba(23,32,51,.08);border-radius:999px;padding:6px 9px;font-size:0.5625rem;font-weight:950;letter-spacing:.08em;color:#39465d;box-shadow:0 5px 15px rgba(24,32,51,.08)}.card-footer{display:flex;align-items:end;justify-content:space-between;gap:12px;margin-top:14px}.card-footer .tags{margin-top:0}.open-lab{font-size:0.625rem;font-weight:950;color:#315ed8;white-space:nowrap}.tag{background:#f7f8fa;border-color:#dfe4eb;font-size:0.5625rem}.lab-bridge .card-scene{background:#e9eff8}.lab-racer .card-scene{background:#f8eee1}.lab-egg .card-scene{background:#eeecfa}.lab-catapult .card-scene{background:#edf3f8}.lab-balloon .card-scene{background:#eaf6f5}.lab-tower .card-scene{background:#f1edfa}
.home-quality{display:grid;grid-template-columns:repeat(3,1fr);gap:0;margin-top:20px;overflow:hidden;border-radius:24px}.home-quality>div{display:flex;gap:13px;padding:18px 20px;border-right:1px solid var(--line)}.home-quality>div:last-child{border-right:0}.quality-icon{display:grid;place-items:center;flex:0 0 auto;width:38px;height:38px;border-radius:12px;background:#edf3ff;color:#315ed8;font-weight:950}.home-quality strong{display:block;font-size:0.8125rem}.home-quality p{margin:4px 0 0;color:var(--muted);font-size:0.65625rem;line-height:1.5}
/* shared v0.7 lab polish */
.hero h1{letter-spacing:-.05em}.challenge{box-shadow:0 18px 40px rgba(23,34,58,.18)}.steps{gap:9px}.step{background:rgba(255,255,255,.86);border-radius:16px}.step.active{border-color:#b9c9ef;box-shadow:0 9px 24px rgba(49,94,216,.09)}.controls,.results{border-radius:24px}.stage-panel{border-radius:26px;box-shadow:0 18px 48px rgba(24,32,51,.10)}.stage-top{padding:13px 17px}.stage{background:#f5f7fa}.stage:before{opacity:.4}.test{box-shadow:0 12px 26px rgba(217,157,35,.26)}.result-hero{border-radius:17px}.learning-card{border-radius:16px;box-shadow:inset 0 0 0 1px rgba(49,94,216,.02)}
/* Racer v0.7 visual scene */
.racer-stage{background:linear-gradient(180deg,#f7f3ea 0,#edf1f5 58%,#e4e6e8 58%,#e0e2e5 100%)}.racer-stage:before{display:none}.racer-stage svg{min-height:500px}.racer-stage-panel .stage-top{background:#fff}.racer-controls .build-section{background:#fbfcfd;border:1px solid #e6e9ef;border-radius:16px;padding:12px;margin-top:10px}.racer-controls .build-section:first-of-type{border-top:1px solid #e6e9ef}.section-label>span{background:#edf3ff}.picture-chips .chip{background:#fff}.racer-test{background:linear-gradient(135deg,#f6c84f,#efaa35)}.visual-stats{background:#fbfcfd}.visual-stats>div{padding:11px 13px}.live-build-badge{background:#f7f9fc;border:1px solid var(--line);border-radius:12px;padding:8px 10px;text-align:left}.racer-mission{align-items:center}
/* Egg v0.7 visual scene */
.egg-grid{grid-template-columns:330px minmax(560px,1fr) 340px}.egg-controls .build-section{background:#fbfcfd;border:1px solid #e6e9ef;border-radius:16px;padding:12px;margin-top:10px}.egg-stage{background:linear-gradient(180deg,#f4f1fb 0,#edf1f7 68%,#e3e5e8 68%,#e0e2e4 100%)}.egg-stage:before{display:none}.egg-stage svg{min-height:500px}.egg-protection-preview{display:grid;grid-template-columns:repeat(3,1fr);gap:7px;margin-top:10px}.egg-protection-preview div{padding:8px;border:1px solid var(--line);border-radius:11px;background:#fff}.egg-protection-preview span,.egg-protection-preview strong{display:block}.egg-protection-preview span{font-size:0.5rem;color:var(--muted);font-weight:900;letter-spacing:.07em}.egg-protection-preview strong{font-size:0.6875rem;margin-top:2px}.egg-test{font-size:1.125rem;min-height:60px}
@media(max-width:1120px){.premium-hero{grid-template-columns:1fr}.hero-workbench{max-width:760px}.premium-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.home-quality{grid-template-columns:1fr}.home-quality>div{border-right:0;border-bottom:1px solid var(--line)}.home-quality>div:last-child{border-bottom:0}.egg-grid{grid-template-columns:290px minmax(500px,1fr)}.egg-grid .results{grid-column:1/-1;position:static}}
@media(max-width:760px){.premium-hero{padding-top:8px}.premium-hero-copy h1{font-size:3.3125rem}.premium-hero-copy p{font-size:0.9375rem}.hero-workbench{border-radius:24px}.premium-grid{grid-template-columns:1fr}.premium-card .card-scene{height:205px}.premium-section-head{display:block}.premium-section-head p{text-align:left;margin-top:6px}.card-footer{align-items:center}.egg-grid{display:block}.egg-controls,.egg-grid .results{position:static;margin-bottom:10px}.egg-stage svg{min-height:365px}.hero-flow i{display:none}}

/* v0.8 art-consistency pass */
.home-body{background:linear-gradient(180deg,#fbfaf7 0,#f2f0ea 100%)}
.home-shell{max-width:1520px}
.premium-card{box-shadow:0 16px 42px rgba(24,32,51,.09)}
.premium-card .card-scene{height:236px}
.premium-card h3{font-size:1.625rem}
.panel,.controls,.results,.stage-panel{border-color:#d7dde7}
.stage-panel{box-shadow:0 20px 54px rgba(24,32,51,.11)}
.stage-top{background:linear-gradient(180deg,#fff 0,#fbfcfd 100%)}
.status{background:linear-gradient(180deg,#fff 0,#fbfcfd 100%)}
.hintbar{border-color:#d6dff1;background:linear-gradient(135deg,#fbfdff,#f2f6ff)}
.controls .group,.results .group{position:relative}
.controls .group label{font-size:0.625rem}
.controls,.results{padding:17px}
.controls .panel-title,.results .panel-title{margin-bottom:16px}
.controls .coach,.results .coach,.learning-card{box-shadow:0 10px 22px rgba(24,32,51,.05)}
.compare-strip{display:flex;align-items:center;justify-content:center;gap:14px;margin-top:10px;padding:10px 12px;border:1px solid var(--line);border-radius:14px;background:#fbfcfe}.compare-strip span{display:block;font-size:0.5625rem;color:var(--muted);font-weight:900;letter-spacing:.08em}.compare-strip strong{display:block;font-size:0.875rem}.compare-strip b{color:#315ed8}

/* shared v0.8 stage scenes */
.catapult-grid,.balloon-grid,.tower-grid{grid-template-columns:310px minmax(540px,1fr) 340px}
.catapult-stage,.balloon-stage,.tower-stage{background:linear-gradient(180deg,#f7f9fc 0,#edf2f7 100%)}
.catapult-stage:before,.balloon-stage:before,.tower-stage:before{display:none}
.catapult-stage svg,.balloon-stage svg,.tower-stage svg{min-height:500px}
.catapult-stage-panel,.balloon-stage-panel,.tower-stage-panel{overflow:hidden}
.catapult-shell .challenge,.balloon-shell .challenge,.tower-shell .challenge{min-width:255px}
.egg-stage-panel,.catapult-stage-panel,.balloon-stage-panel,.tower-stage-panel{border-radius:28px}

/* catapult */
.catapult-shell .controls,.catapult-shell .results{border-radius:24px}
.catapult-shell .group .chips .chip,.balloon-shell .group .chips .chip,.tower-shell .group .chips .chip,.egg-shell .group .chips .chip{background:#fff}
.catapult-shell .test{background:linear-gradient(135deg,#f7c956,#ec8c3d);color:#2f2200}

/* balloon car */
.balloon-stage{background:linear-gradient(180deg,#f4fbfc 0,#edf2f7 100%)}
.balloon-shell .test{background:linear-gradient(135deg,#f6c84f,#efa934)}
.balloon-shell .stage-top span{max-width:240px;text-align:right}

/* tower */
.tower-stage{background:linear-gradient(180deg,#f6f5fb 0,#edf1f7 100%)}
.tower-shell .test{background:linear-gradient(135deg,#f6c84f,#efaa35)}

/* egg drop */
.egg-stage{background:linear-gradient(180deg,#f7f5fc 0,#eef2f8 100%)}
.egg-stage-panel .egg-protection-preview{padding:0 12px 10px}
.egg-protection-preview div{box-shadow:0 5px 14px rgba(24,32,51,.04)}

@media(max-width:1230px){.catapult-grid,.balloon-grid,.tower-grid{grid-template-columns:290px minmax(500px,1fr)}.catapult-grid .results,.balloon-grid .results,.tower-grid .results{grid-column:1/-1;position:static}}
@media(max-width:820px){.catapult-grid,.balloon-grid,.tower-grid{display:block}.catapult-shell .controls,.catapult-shell .results,.balloon-shell .controls,.balloon-shell .results,.tower-shell .controls,.tower-shell .results{position:static;margin-bottom:10px}.catapult-stage-panel,.balloon-stage-panel,.tower-stage-panel{margin-bottom:10px}.catapult-stage svg,.balloon-stage svg,.tower-stage svg{min-height:360px}}

/* v0.13 platform quality pass */
:root{
  --surface:#ffffff;--surface-2:#f7f9fc;--surface-3:#eef3f8;--navy:#17223a;
  --hair:#d8dee8;--focus:#315ed8;--warm:#f6c84f;--warm-2:#ef9d3c;
}
body{background:linear-gradient(180deg,#fbfaf7 0,#f3f1ec 52%,#eeece6 100%)}
.shell{padding-top:20px}
.back{background:rgba(255,255,255,.72);border:1px solid rgba(216,222,232,.9);box-shadow:0 5px 14px rgba(24,32,51,.04)}
.hero{padding-top:14px}.hero p{font-size:0.96875rem}.challenge{border:1px solid rgba(255,255,255,.12);box-shadow:0 20px 46px rgba(23,34,58,.20)}
.steps{margin-bottom:14px}.step{min-height:55px;box-shadow:0 4px 12px rgba(24,32,51,.035)}
.panel{background:rgba(255,255,255,.985);border-color:var(--hair);box-shadow:0 16px 44px rgba(24,32,51,.085)}
.controls,.results{padding:18px}.panel-title h2{font-size:1.25rem}.panel-title p{font-size:0.71875rem}
.controls>.group,.controls>.build-section{background:linear-gradient(180deg,#fff,#fbfcfe);border:1px solid #e5e9f0;border-radius:16px;padding:11px 12px;margin-top:10px}
.controls>.group:first-of-type,.controls>.build-section:first-of-type{margin-top:0}
.controls>.group label{margin-bottom:8px}
.range-row input[type=range]{accent-color:var(--focus)}
.value{background:#fff;border-color:#dbe1ea;box-shadow:inset 0 1px 0 #fff}
.chip{background:#fff;border-color:#dbe1ea;box-shadow:0 3px 9px rgba(24,32,51,.025)}
.chip.active{background:#edf3ff;border-color:#315ed8;box-shadow:0 6px 16px rgba(49,94,216,.08)}
.coach{background:linear-gradient(145deg,#f7faff,#edf3ff);border-color:#ccd8f1}
.stage-panel{border-radius:28px;box-shadow:0 24px 60px rgba(24,32,51,.12);overflow:hidden}
.stage-top{min-height:48px;padding:13px 17px}.stage-top strong{font-size:0.84375rem}.stage-top span{font-size:0.65625rem}
.status{min-height:44px;align-items:center;padding:10px 16px}.status strong{color:#303a4d}
.test{min-height:58px;font-size:1.0938rem;letter-spacing:.01em;border-radius:17px;box-shadow:0 14px 28px rgba(217,157,35,.28)}
.test:hover{transform:translateY(-2px)}.reset{min-height:43px}
.result-hero{padding:15px;border-radius:17px;box-shadow:inset 0 1px 0 rgba(255,255,255,.75)}
.metric{background:linear-gradient(180deg,#fff,#f9fbfd);border-color:#e0e5ed;padding:11px}
.metric strong{font-size:1.25rem}.learning-card{background:linear-gradient(145deg,#fff,#f7faff);border-color:#d9e1ef;box-shadow:0 10px 24px rgba(24,32,51,.045)}
.learning-card:before{content:"OBSERVE → EXPLAIN → TRY AGAIN";display:block;font-size:0.5rem;font-weight:950;letter-spacing:.13em;color:#315ed8;margin-bottom:8px}
.learning-card .try-next{background:#f4f7fc;border:1px dashed #cbd5e6;border-radius:10px;padding:8px 9px;margin-top:10px}
.advanced{padding-top:3px}.advanced summary{padding:6px 0}

/* Home v0.13 */
.premium-hero{gap:42px;padding-top:30px}.premium-hero-copy h1{max-width:760px}.hero-workbench{box-shadow:0 34px 82px rgba(23,34,58,.18);border-radius:36px}
.premium-section-head{margin-top:26px}.premium-grid{gap:20px}.premium-card{border-radius:28px;box-shadow:0 18px 48px rgba(24,32,51,.085);transition:transform .2s ease,box-shadow .2s ease,border-color .2s ease}
.premium-card:hover{transform:translateY(-6px);box-shadow:0 28px 70px rgba(24,32,51,.15)}
.premium-card .card-scene{height:242px;background:#eff3f8}.premium-card .card-copy{padding:20px 20px 19px}.premium-card h3{font-size:1.6875rem}
.scene-badge{top:15px;left:15px;padding:7px 10px;background:rgba(255,255,255,.94);backdrop-filter:blur(8px);box-shadow:0 7px 18px rgba(24,32,51,.08)}
.open-lab{display:inline-flex;align-items:center;min-height:34px;padding:0 9px;border-radius:999px;background:#edf3ff;color:#315ed8}
.home-quality{margin-top:24px}.home-quality>div{padding:20px 22px}

/* richer per-lab stage surfaces */
.catapult-stage,.balloon-stage,.tower-stage,.egg-stage,.racer-stage{position:relative}
.catapult-stage svg,.balloon-stage svg,.tower-stage svg,.egg-stage svg,.racer-stage svg{filter:saturate(1.02) contrast(1.01)}
.catapult-stage-panel .stage-top,.balloon-stage-panel .stage-top,.tower-stage-panel .stage-top,.egg-stage-panel .stage-top,.racer-stage-panel .stage-top{background:linear-gradient(180deg,#fff,#fbfcfe)}

/* young-user clarity */
.hintbar{border-radius:17px;padding:12px 15px}.hintbar strong{font-size:0.84375rem}.hintbar span{font-size:0.65625rem}
.section-label>span,.hint-icon{box-shadow:inset 0 0 0 1px rgba(49,94,216,.05)}
@media(max-width:820px){.controls>.group,.controls>.build-section{padding:10px}.premium-card .card-scene{height:218px}.hero p{font-size:0.875rem}}

/* v0.13 audit + clean-up pass */
body{background:linear-gradient(180deg,#faf9f6 0,#f1efe9 56%,#ece9e2 100%)}
.hero-workbench,.premium-card,.panel,.stage-panel{backdrop-filter:saturate(1.02)}
.premium-card .card-scene{background:linear-gradient(180deg,#f3f6fa 0,#edf1f6 100%)}
.premium-card p{color:#616c7f}
.stage{box-shadow:inset 0 1px 0 rgba(255,255,255,.8)}
.stage-panel{box-shadow:0 22px 56px rgba(24,32,51,.11)}
.status,.stage-top{border-color:#e4e8ef}
.controls>.group,.controls>.build-section{box-shadow:inset 0 1px 0 rgba(255,255,255,.7)}
.result-hero{background:linear-gradient(180deg,#fff,#f8fafc)}
.compare-strip{background:linear-gradient(180deg,#fff,#f9fbfe)}

/* catapult-specific repair */
.catapult-stage{background:linear-gradient(180deg,#f5f8fc 0,#edf2f7 100%)}
.catapult-stage-panel .status{justify-content:space-between}
.catapult-shell .result-hero p{max-width:32ch}

/* make stage objects read more like tabletop prototypes */
.balloon-stage{background:linear-gradient(180deg,#f3fafb 0,#ecf2f7 100%)}
.tower-stage{background:linear-gradient(180deg,#f6f4fb 0,#ecf1f7 100%)}
.egg-stage{background:linear-gradient(180deg,#f6f4fb 0,#edf2f8 100%)}
.racer-stage{background:linear-gradient(180deg,#f8f4ec 0,#edf1f5 58%,#e4e6e8 58%,#e0e2e5 100%)}
/* Unified overview cards for the repaired lab scenes. */
.home-body{background:#f5f4ef}
.home-shell .premium-card,.home-shell .hero-workbench,.home-shell .home-quality{box-shadow:none;border:1px solid #d8ddd9}
.home-shell .premium-card:hover{box-shadow:0 8px 22px rgba(38,52,73,.10)}
.home-shell .premium-card .card-scene{background:#f6f7f4;height:242px}
.home-shell .premium-card .card-scene img{display:block;width:100%;height:100%;object-fit:cover}
.home-shell .scene-badge{background:#263449;color:#fff;border-radius:8px;box-shadow:none;backdrop-filter:none}
.home-shell .home-mission{background:#263449;box-shadow:none}
@media(max-width:760px){.home-shell .premium-card .card-scene{height:205px}}
.home-shell .hero-workbench{overflow:hidden;background:#f6f7f4;border-radius:18px}
.home-shell .hero-workbench img{display:block;width:100%;height:100%;object-fit:cover}

/* Short explanations available next to the engineering results in every lab. */
.kid-explainer{display:flex;gap:12px;padding:15px;margin:16px 0;background:#f0f5ee;border:1px solid #cbd9c9;border-radius:14px;color:#263449}
.kid-explainer-icon{flex:0 0 30px;width:30px;height:30px;display:grid;place-items:center;background:#d7e9d8;border-radius:9px;font-weight:900}
.kid-explainer h3{font-size:0.9375rem;line-height:1.2;margin:0 0 6px}
.kid-explainer p{font-size:0.75rem;line-height:1.55;margin:0 0 6px}
.kid-explainer p.kid-try{font-weight:700;margin:0}

/* One quiet build marker for distinguishing extracted revisions. */
.build-id{max-width:1540px;margin:24px auto 8px;text-align:right;color:#7d8791;font:800 10px/1.4 ui-sans-serif,system-ui,sans-serif;letter-spacing:.1em}