:root{color-scheme:light;--page:#fff;--surface:#f6f8fb;--surface-line:#d8e2ee;--hover:#fff;--button-ink:var(--body);--toward:var(--body);--accent:#2563eb;--accent-rgb:37,99,235;--ink:#111827;--muted:var(--body);--line:#d8e2ee;--body:#334155;--section-line:#b9c8db;--link:#1d4ed8;--accent-hover:#1d4ed8;--accent-soft:#eff6ff;--on-accent:#fff}
*{box-sizing:border-box}html,body{margin:0;min-width:280px;min-height:100%;background:var(--page);color:var(--ink)}body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Microsoft YaHei",sans-serif;-webkit-font-smoothing:antialiased}main{position:relative;width:min(100%,1440px);min-height:100svh;margin:auto;padding:clamp(24px,4vw,64px) clamp(24px,5vw,80px) 24px;display:flex;flex-direction:column}.hero{display:grid;grid-template-columns:minmax(0,1.05fr) minmax(0,1fr);gap:clamp(24px,4vw,64px);align-items:center;flex:1;min-height:0;padding-block:28px 40px}.intro{grid-column:2;grid-row:1;min-width:0;padding-bottom:16px}h1{font-size:clamp(2rem,4vw,3.65rem);font-weight:550;letter-spacing:-.055em;line-height:1.075;margin:0}h1{overflow-wrap:anywhere}h1 span{display:block}.toward{font-size:.49em;font-weight:400;letter-spacing:-.025em;line-height:1.5;color:var(--toward);margin-bottom:.55em}.promise{margin:32px 0 0;letter-spacing:-.035em;font-weight:400}.build-line{display:block;font-size:clamp(1.125rem,1.8vw,1.5rem);line-height:1.5;color:var(--muted)}.phrase-line{display:block;min-height:2.65em;max-width:100%;margin-top:3px;font-size:clamp(1.5rem,2.8vw,2.5rem);line-height:1.3;font-weight:500;color:var(--accent);transition:color .5s;overflow-wrap:break-word}.typing-caret{display:inline-block;width:1.5px;height:.91em;background:currentColor;margin-left:4px;vertical-align:-.04em;opacity:0;transition:opacity .25s}.is-typing .typing-caret{opacity:.75}#scene{grid-column:1;grid-row:1;width:100%;height:clamp(320px,48vw,540px);max-height:70svh;outline:none;cursor:grab;touch-action:none}#scene.orbiting{cursor:grabbing}#scene:focus-visible{outline:2px solid var(--accent);outline-offset:3px;border-radius:16px}canvas{display:block;width:100%;height:100%}.toolbar{display:flex;align-items:center;justify-content:space-between;gap:20px;padding-top:20px;border-top:1px solid var(--line)}.models{display:flex;gap:4px;padding:5px;background:var(--surface);border:1px solid var(--surface-line);border-radius:18px}.controls{display:flex;gap:8px}button{flex-shrink:0;width:44px;height:44px;display:grid;place-items:center;padding:0;border:1px solid transparent;border-radius:12px;background:transparent;color:var(--button-ink);cursor:pointer;transition:color .25s,background .25s,border-color .25s,transform .25s}button:hover{background:var(--hover);color:var(--accent);transform:translateY(-1px)}button:focus-visible{outline:2px solid var(--accent);outline-offset:3px}button svg{fill:none;stroke:currentColor;stroke-width:1.4;stroke-linecap:round;stroke-linejoin:round}.models button[aria-pressed="true"]{color:var(--accent);border-color:rgba(var(--accent-rgb),.16);background:rgba(var(--accent-rgb),.08)}.controls button{border-color:var(--line);border-radius:50%;color:var(--button-ink)}.controls button:hover,.controls button[aria-pressed="true"]{color:var(--accent);border-color:rgba(var(--accent-rgb),.3)}#loading{display:none}#error{position:fixed;inset:40% 20% auto;text-align:center;padding:20px;background:var(--page);font-size:16px;line-height:1.8;z-index:3}.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}
@media(orientation:portrait),(max-width:720px){main{padding:36px clamp(24px,6vw,60px) 22px}.hero{display:flex;flex-direction:column;gap:8px;justify-content:center;padding:8px 0 20px}.intro{order:0;width:100%;max-width:540px;padding:0}h1{font-size:clamp(2rem,7.2vw,3.25rem);line-height:1.07}.toward{font-size:.5em;margin-bottom:.4em}.promise{margin-top:22px}.build-line{font-size:1.125rem}.phrase-line{font-size:clamp(1.45rem,5.6vw,2.2rem);min-height:2.6em;margin-top:1px}#scene{order:1;width:100%;max-width:540px;height:clamp(290px,43svh,460px);max-height:none;flex-shrink:0}.toolbar{padding-top:16px;width:100%;max-width:640px;margin-inline:auto}.models{gap:2px}button{width:40px;height:40px}}
@media(max-width:600px){.models{display:grid;grid-template-columns:repeat(5,40px);gap:4px 6px;padding:5px;border-radius:16px}.controls{flex-direction:column;gap:4px;padding-left:14px;border-left:1px solid var(--line)}.toolbar{gap:12px;justify-content:space-between}.controls button{width:40px;height:40px}#scene{height:clamp(270px,39svh,390px)}.hero{padding-bottom:12px}.phrase-line{min-height:1.4em}}
@media(max-width:360px){main{padding-inline:20px}.models{grid-template-columns:repeat(5,36px);gap:4px}.models button{width:36px;height:40px}.controls{padding-left:8px}.controls button{width:36px;height:40px}h1{font-size:1.75rem}.phrase-line{font-size:1.375rem}.toolbar{gap:8px}}
@media(orientation:landscape) and (max-height:600px) and (min-width:721px){main{padding-top:20px}.hero{padding-block:0 18px}.intro{padding-bottom:0}h1{font-size:clamp(2rem,3.8vw,2.65rem)}.promise{margin-top:18px}.phrase-line{font-size:1.7rem;min-height:1.4em}#scene{height:65svh;min-height:240px}.toolbar{padding-top:12px}.models button{width:36px;height:36px}}
@media(prefers-reduced-motion:reduce){*,*::before,*::after{transition:none!important;animation:none!important;scroll-behavior:auto!important}}

@media(orientation:landscape) and (min-width:600px) and (max-width:720px){main{padding:18px 24px}.hero{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:24px;padding:0 0 16px}.intro{grid-column:2;grid-row:1}h1{font-size:1.65rem}.promise{margin-top:16px}.build-line{font-size:1rem}.phrase-line{font-size:1.25rem;min-height:2.6em}#scene{grid-column:1;grid-row:1;height:65svh;min-height:220px}.toolbar{padding-top:12px}.models button{width:36px;height:36px}.models{display:flex;gap:2px}.controls{flex-direction:row;padding-left:0;border:0;gap:6px}}

:root[data-theme="dark"]{color-scheme:dark;--page:#080b10;--ink:#f1f5f9;--muted:var(--body);--toward:var(--body);--line:#344155;--surface:#101827;--surface-line:#344155;--hover:#192230;--button-ink:var(--body);--accent:#60a5fa;--accent-rgb:96,165,250;--body:#e2e8f0;--section-line:#46566c;--link:#93c5fd;--accent-hover:#93c5fd;--accent-soft:#122443;--on-accent:#07152e}
.theme-switch{position:absolute;top:clamp(20px,3vw,40px);right:clamp(24px,5vw,80px);width:40px;height:40px;z-index:1;border:1px solid var(--line);border-radius:50%;color:var(--button-ink);background:var(--page)}
.theme-sun{display:none}:root[data-theme="dark"] .theme-sun{display:block}:root[data-theme="dark"] .theme-moon{display:none}
@media(orientation:portrait),(max-width:720px){.theme-switch{top:22px;right:clamp(24px,6vw,60px);width:36px;height:36px}}
@media(orientation:landscape) and (max-height:600px){.theme-switch{top:12px;width:32px;height:32px}}

@media(max-width:600px){.models{grid-template-columns:40px repeat(5,32px);gap:4px}.models button{width:32px;height:40px}.models button[data-model="home"]{grid-row:span 2;width:40px;height:84px;border-radius:12px}.controls{padding-left:8px}.toolbar{gap:8px}}
@media(max-width:360px){.models{grid-template-columns:32px repeat(5,30px);gap:2px;padding:4px}.models button{width:30px}.models button[data-model="home"]{width:32px;height:82px}.controls{padding-left:5px}.controls button{width:32px}.toolbar{gap:6px}}