*{box-sizing:border-box}
:root{color-scheme:light;--ink:#1d1d1f;--muted:#6e6e73;--line:#e5e5e7;--accent:#0071e3;--paper:#fff;--surface:#f5f5f7}
html{scroll-behavior:smooth;scroll-padding-top:24px}
body{margin:0;background:var(--paper);color:var(--ink);font-family:-apple-system,BlinkMacSystemFont,"SF Pro Display","SF Pro Text","Helvetica Neue","PingFang SC","Microsoft YaHei",sans-serif;font-size:14px;-webkit-font-smoothing:antialiased}
button,a,input,summary{-webkit-tap-highlight-color:transparent;touch-action:manipulation}
button{font:inherit;color:inherit;cursor:pointer;border:0;background:transparent}button:disabled{opacity:.4;cursor:default}
button:focus-visible,a:focus-visible,input:focus-visible,summary:focus-visible{outline:3px solid #0071e388;outline-offset:4px}
a{color:var(--accent);text-decoration:none}a:hover{text-decoration:underline}
p{line-height:1.7}h1,h2,p,dl,dd{margin:0}h2{font-size:17px;font-weight:600;letter-spacing:-.3px}
.site-header{border-bottom:1px solid var(--line)}
.header-inner{height:64px;max-width:1200px;padding:0 32px;margin:auto;display:flex;align-items:center;justify-content:space-between}
.brand{color:var(--ink);font-size:22px;font-weight:600;letter-spacing:-.8px}.brand:hover{text-decoration:none}
nav{display:flex;gap:26px;font-size:12px}nav a{color:var(--muted)}nav a:hover{color:var(--ink)}
main{max-width:1200px;padding:0 32px;margin:auto}
.hero{padding:40px 0 30px}.hero-top{display:flex;align-items:center;justify-content:space-between;gap:24px}
.product-name{color:var(--muted);font-size:14px;font-weight:500;margin-bottom:8px}
h1{font-size:46px;font-weight:600;letter-spacing:-1.8px;line-height:1.2}.subtitle{margin-top:10px;color:var(--muted);font-size:14px}
.readiness{display:flex;align-items:flex-end;flex-direction:column;gap:14px}.readiness>span{font-size:12px;color:var(--muted)}
#show-result{background:var(--surface);border-radius:30px;padding:11px 18px;font-size:13px}#show-result:hover{background:#ebebed}#show-result span{margin-left:9px;color:var(--muted)}
.summary-metrics{display:flex;gap:44px;margin-top:28px}.summary-metrics>div+div{padding-left:36px;border-left:1px solid var(--line)}
.summary-metrics dt{font-size:11px;color:var(--muted);margin-bottom:6px}.summary-metrics dd{font-size:25px;font-weight:500;letter-spacing:-.7px;font-variant-numeric:tabular-nums}
.player{border:1px solid var(--line);border-radius:24px;overflow:hidden;background:var(--surface)}
.viewport{position:relative;height:clamp(420px,57vh,640px);min-width:0;background:var(--surface)}
.viewport canvas{display:block;width:100%;height:100%;touch-action:none;cursor:grab}.viewport canvas:active{cursor:grabbing}
#loading{position:absolute;inset:0;display:grid;place-items:center;background:var(--surface);z-index:2;color:var(--muted);font-size:13px}
.viewbar{position:absolute;top:18px;left:18px;display:flex;gap:2px;padding:4px;background:#e9e9ebd9;border-radius:24px;backdrop-filter:blur(16px)}
.viewbar button{padding:8px 17px;border-radius:22px;color:var(--muted);font-size:12px}.viewbar button.active{background:#fff;color:var(--ink);box-shadow:0 1px 4px #0000000d}
.scene-bottom{position:absolute;bottom:18px;left:22px;right:22px;display:flex;align-items:center;justify-content:space-between;gap:16px;font-size:11px}
.scene-caption{background:#ffffffd9;backdrop-filter:blur(12px);border-radius:20px;padding:7px 12px;max-width:65%;line-height:1.5}
.scene-options{display:flex;gap:14px;flex-shrink:0;color:var(--muted)}.scene-options label{display:flex;gap:5px;align-items:center;cursor:pointer}.scene-options input{accent-color:var(--ink);width:12px;height:12px;margin:0}
.transport{padding:18px 22px 20px;background:#fff;border-top:1px solid #ededee}
.time-row{display:flex;align-items:center;gap:14px;color:var(--muted);font-size:11px;font-variant-numeric:tabular-nums}.time-row>span{min-width:54px}.time-row>span:last-child{text-align:right}
#timeline{flex:1;min-width:0;cursor:pointer;accent-color:var(--accent);height:4px;margin:8px 0}
.control-row{display:flex;align-items:center;gap:28px;margin-top:16px}.play-controls{display:flex;align-items:center;gap:6px}
.play-controls button{height:36px;min-width:34px;border-radius:20px}.icon-button{font-size:22px;color:var(--muted)}.icon-button:hover{background:var(--surface);color:var(--ink)}
.play-controls .primary{min-width:84px;background:var(--accent);color:#fff;padding:0 22px;font-size:13px}.play-controls .primary:hover{background:#0077ed}
.speed{display:flex;align-items:center;gap:2px;background:var(--surface);padding:3px;border-radius:20px}.speed button{padding:7px 13px;border-radius:18px;color:var(--muted);font-size:11px;white-space:nowrap}.speed button.active{background:#fff;color:var(--ink);box-shadow:0 1px 4px #00000012}
.frame-label{margin-left:auto;color:#929297;font-size:10px;font-variant-numeric:tabular-nums}
.sequence{padding:30px 0}.section-heading{display:flex;align-items:center;justify-content:space-between;gap:12px}.section-heading>span{color:var(--muted);font-size:11px}
.moves{display:flex;gap:8px;margin-top:16px;flex-wrap:wrap}.moves button{min-width:48px;height:40px;border:1px solid var(--line);border-radius:12px;font-size:13px;font-variant-numeric:tabular-nums}.moves button:hover{background:var(--surface)}.moves button.active{border-color:var(--accent);color:var(--accent);background:#f2f7ff}
.scramble{color:var(--muted);font-size:11px;margin-top:13px}.scramble code{color:var(--ink);font-family:ui-monospace,SFMono-Regular,Consolas,monospace;font-size:11px;margin-left:12px;line-height:1.8}
.details{border-top:1px solid var(--line);border-bottom:1px solid var(--line);scroll-margin-top:20px}.details>summary{list-style:none;cursor:pointer;padding:24px 0;display:flex;align-items:center;gap:16px;font-size:17px;font-weight:500}.details>summary::-webkit-details-marker{display:none}.details>summary::after{content:'+';font-size:23px;line-height:1;font-weight:300;margin-left:auto;color:var(--muted)}.details[open]>summary::after{content:'−'}.summary-hint{font-size:12px;color:var(--muted);font-weight:400}
.details-body{padding:4px 0 28px}.inspection{display:grid;grid-template-columns:1fr 1fr;gap:80px;align-items:center;max-width:780px;margin:0 auto 30px}.cube-state{max-width:300px;width:100%;justify-self:center}
.cube-net{display:grid;grid-template-columns:repeat(4,1fr);grid-template-rows:repeat(3,52px);gap:5px;margin-top:22px}.cube-face{position:relative;display:grid;grid-template-columns:repeat(3,1fr);gap:2px;padding:3px;background:#dedee1;border-radius:4px}.cube-face span{border-radius:2px;min-width:0}.cube-face i{position:absolute;inset:0;display:grid;place-items:center;font-style:normal;color:#1d1d1f66;font-size:9px;pointer-events:none}.net-note{color:var(--muted);font-size:10px;text-align:center;margin-top:12px}
.metrics>div{display:flex;align-items:center;justify-content:space-between;gap:20px;padding:10px 0;border-bottom:1px solid #f0f0f2;font-size:12px}.metrics span{color:var(--muted)}.metrics strong{font-weight:500;font-variant-numeric:tabular-nums}.metrics p{margin-top:12px;color:var(--muted);font-size:11px}
.optimization{border-top:1px solid var(--line);padding-top:25px;margin-top:26px}.optimization[hidden]{display:none}.optimization-metrics{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:24px;margin-top:24px}.optimization-metrics>div{display:flex;flex-direction:column;gap:8px}.optimization-metrics span{font-size:11px;color:var(--muted)}.optimization-metrics strong{font-size:22px;font-weight:500;letter-spacing:-.5px;font-variant-numeric:tabular-nums}.optimization p{color:var(--muted);font-size:12px;margin-top:20px;max-width:950px}
.evidence{border-top:1px solid var(--line);margin-top:28px;padding-top:26px}.evidence>p{color:var(--muted);font-size:12px;margin-top:16px}.evidence dl{max-width:650px;margin-top:18px}.evidence dl>div{display:flex;justify-content:space-between;gap:25px;padding:8px 0;font-size:12px}.evidence dt{color:var(--muted)}.evidence dd{text-align:right}.evidence .hash{font:10px/1.7 ui-monospace,SFMono-Regular,Consolas,monospace;overflow-wrap:anywhere}.reference{display:inline-block;margin-top:15px;font-size:12px}
footer{max-width:1200px;margin:auto;padding:24px 32px 32px;display:flex;justify-content:space-between;gap:20px;color:#86868b;font-size:11px}
@media(min-width:1600px){main,.header-inner,footer{max-width:1320px}}
@media(max-width:760px){main{padding:0 20px}.header-inner{padding:0 20px}.hero{padding-top:30px}h1{font-size:38px}.viewport{height:480px}.frame-label{display:none}.control-row{justify-content:space-between;gap:12px}.inspection{gap:35px}.optimization-metrics{grid-template-columns:repeat(2,minmax(0,1fr));row-gap:25px}.moves button{min-width:42px}footer{padding-left:20px;padding-right:20px}}
@media(max-width:480px){.header-inner{height:58px}.brand{font-size:21px}nav{gap:20px;font-size:11px}.hero{padding:28px 0 24px}.hero-top{gap:12px;align-items:flex-end}.product-name{font-size:12px;margin-bottom:9px}h1{font-size:34px;letter-spacing:-1.2px}.subtitle{font-size:12px;margin-top:9px}.readiness{gap:10px;padding-bottom:2px}.readiness>span{font-size:10px}#show-result{font-size:11px;padding:9px 12px;white-space:nowrap}#show-result span{display:none}.summary-metrics{gap:0;justify-content:space-between;margin-top:25px}.summary-metrics>div+div{padding-left:18px}.summary-metrics dt{font-size:10px}.summary-metrics dd{font-size:22px}.player{border-radius:20px}.viewport{height:370px}.viewbar{top:14px;left:14px}.viewbar button{font-size:11px;padding:7px 13px}.scene-bottom{left:14px;right:14px;bottom:14px;gap:10px;align-items:flex-start;flex-direction:column;font-size:10px}.scene-caption{max-width:100%;padding:6px 10px}.scene-options{gap:14px;margin-left:2px}.transport{padding:14px 12px 16px}.time-row{gap:9px;font-size:10px}.time-row>span{min-width:49px}.control-row{flex-wrap:wrap;gap:12px}.play-controls{gap:2px}.play-controls button{min-width:27px;height:34px}.play-controls .primary{min-width:61px;padding:0 14px;font-size:12px}.speed{gap:0;padding:3px}.speed button{font-size:10px;padding:7px 7px}.sequence{padding:25px 0}h2{font-size:16px}.moves{gap:7px}.moves button{width:calc((100% - 28px)/5);min-width:0;height:38px}.scramble code{margin-left:5px;font-size:10px}.details>summary{font-size:16px;padding:22px 0}.summary-hint{font-size:11px}.inspection{grid-template-columns:1fr;gap:22px}.cube-state{max-width:270px}.metrics{width:100%}.optimization-metrics strong{font-size:21px}.evidence dl>div{font-size:11px;gap:14px}footer{flex-direction:column;gap:9px;font-size:10px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}

/* Six orthographic views share the recorded cubelet poses with the main view. */
.player-stage{display:grid;grid-template-columns:minmax(0,1fr) 264px}
.live-faces{background:#fff;border-left:1px solid var(--line);padding:24px 18px 18px;display:flex;flex-direction:column;min-width:0}
.live-faces h2{font-size:14px;letter-spacing:0}.live-faces .section-heading>span{font-size:10px;white-space:nowrap}
.face-views{position:relative;flex:1;min-height:342px;margin:14px 0 10px}
#face-canvas{display:block;position:absolute;inset:0;width:100%;height:100%}
.face-labels{position:absolute;inset:0;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));grid-template-rows:repeat(3,1fr);pointer-events:none}
.face-labels>span{align-self:end;justify-self:center;font-size:11px;font-weight:500;padding-bottom:3px}
.face-labels small{font-size:10px;font-weight:400;color:var(--muted);margin-left:5px}
.live-note{font-size:10px;color:var(--muted);text-align:center;line-height:1.5}
@media(max-width:900px){.player-stage{grid-template-columns:minmax(0,1fr) 228px}.live-faces{padding:20px 12px 16px}.scene-bottom{align-items:flex-start;flex-direction:column;gap:8px}.scene-caption{max-width:100%}}
@media(max-width:640px){.player-stage{grid-template-columns:1fr}.live-faces{border-left:0;border-top:1px solid var(--line);padding:18px 18px 14px}.face-views{min-height:0;height:216px;flex:none;margin:8px 0 10px}.face-labels{grid-template-columns:repeat(3,minmax(0,1fr));grid-template-rows:repeat(2,1fr)}.live-note{font-size:9px}.live-faces h2{font-size:13px}}

/* Shared presentation language control. */
nav{align-items:center}.language-toggle,#language-toggle{min-width:42px;height:30px;padding:0 10px;border:1px solid var(--line);border-radius:18px;font-size:11px;color:var(--ink);background:#fff;white-space:nowrap}
html[lang=en] h1{font-size:42px;letter-spacing:-1.5px}html[lang=en] .hero-top{flex-wrap:wrap}html[lang=en] .readiness{margin-left:auto}
@media(max-width:480px){nav{gap:12px}html[lang=en] nav{gap:10px;font-size:10px}html[lang=en] .brand{font-size:18px}html[lang=en] h1{font-size:30px}html[lang=en] .readiness{align-items:flex-start;margin-left:0}html[lang=en] .summary-metrics dt{font-size:9px}html[lang=en] .summary-hint{font-size:10px}html[lang=en] .scene-options{flex-wrap:wrap}}

footer{flex-wrap:wrap}footer>a{color:var(--muted);white-space:nowrap}

[hidden]{display:none!important}.player-toolbar{display:flex;align-items:center;justify-content:space-between;padding:14px 22px;background:#fff;border-bottom:1px solid var(--line);font-size:12px}.mode-tabs{display:flex;background:var(--surface);border-radius:22px;padding:3px}.mode-tabs button{border-radius:20px;padding:7px 20px;font-size:12px;color:var(--muted)}.mode-tabs button[aria-selected=true]{background:#fff;color:var(--ink);box-shadow:0 1px 4px #00000012}.pen-readout{position:absolute;right:24px;top:22px;display:flex;flex-direction:column;gap:5px;align-items:flex-end;pointer-events:none}.pen-readout>span{font-size:10px;color:var(--muted)}.pen-readout strong{font-size:24px;font-weight:500;letter-spacing:-.7px;font-variant-numeric:tabular-nums}#replay-loading{position:absolute;inset:0;display:grid;place-items:center;background:var(--surface);z-index:3;color:var(--muted);font-size:13px}#replay-timeline{flex:1;min-width:0;cursor:pointer;accent-color:var(--accent);height:4px}#replay-time{min-width:116px;white-space:nowrap}.viewbar button[aria-pressed=true]{background:#fff;color:var(--ink);box-shadow:0 1px 4px #0000000d}#policy-video{display:block;width:100%;height:clamp(420px,57vh,640px);background:var(--surface);object-fit:contain}#video-phase{min-height:70px;display:flex;justify-content:center;align-items:center;background:#fff;color:var(--muted);font-size:12px}.replay-note{font-size:11px;color:var(--muted);margin:14px 2px 0;line-height:1.7}.pen-evidence{border-top:0;margin-top:0;padding-top:0}.pen-evidence dl{max-width:960px}.pen-evidence dl>div{justify-content:flex-start;padding:12px 0;border-bottom:1px solid #f0f0f2;line-height:1.8}.pen-evidence dt{min-width:100px;flex-shrink:0}.pen-evidence dd{text-align:left}.moves button{width:auto;min-width:96px;padding:0 16px;font-size:12px}.moves button.active{border-color:var(--accent);color:var(--accent);background:#f2f7ff}#phases{gap:10px}html[lang=en] .pen-evidence dt{min-width:110px}
@media(max-width:640px){.player-toolbar{padding:12px 14px}.pen-readout{right:16px;top:18px}.pen-readout strong{font-size:20px}.scene-options{font-size:10px}.moves button{font-size:11px;padding:0 12px;min-width:0;flex:1 0 auto}.pen-evidence dl>div{flex-direction:column;gap:4px}.pen-evidence dt{min-width:0}.scene-bottom{align-items:flex-start;flex-direction:column;gap:8px}#policy-video{height:370px}.summary-metrics dt{font-size:10px}html[lang=en] .summary-metrics>div+div{padding-left:10px}}