*{box-sizing:border-box}html,body{margin:0;min-height:100%;font-family:Inter,system-ui,-apple-system,"Segoe UI","Microsoft YaHei",sans-serif}body{background:var(--bg);color:var(--text);transition:.2s}.page{min-height:100vh;max-width:1100px;margin:auto;padding:28px 46px 120px}.topbar{display:flex;align-items:center}.brand{display:flex;align-items:center;gap:14px}.logo{width:58px;height:58px;border-radius:19px;display:grid;place-items:center;font-weight:900;font-size:22px;color:white;background:linear-gradient(135deg,var(--accent),#1db5f2);box-shadow:0 12px 30px #434cff33}.brand-name{font-size:25px;font-weight:800}.brand-sub{color:var(--muted);margin-top:2px}.main{text-align:center;padding-top:80px}.powered{color:#6bd6ff;letter-spacing:3px}.main h1{font-size:48px;margin:18px 0;color:var(--title)}.desc{color:var(--muted);font-size:19px}.chat{text-align:left;margin-top:72px}.label{color:var(--muted);font-weight:700;margin-bottom:10px}.bubble{background:var(--card);border:1px solid var(--border);border-radius:24px;padding:19px;font-size:18px;box-shadow:var(--shadow)}.footer{color:var(--muted2);margin-top:52px}.privacy{color:var(--muted);margin-top:18px}.composer{position:fixed;bottom:28px;left:50%;transform:translateX(-50%);width:min(860px,calc(100% - 34px));background:var(--composer);border:1px solid var(--border);border-radius:25px;padding:10px 10px 10px 20px;display:flex;gap:8px;box-shadow:var(--shadow)}.composer textarea{flex:1;resize:none;background:transparent;border:0;outline:0;color:var(--text);font-size:17px;padding:12px}.composer button{width:54px;height:54px;border:0;border-radius:17px;background:linear-gradient(135deg,var(--accent),#1db5f2);color:white;font-size:30px;font-weight:bold;cursor:pointer}
html[data-theme=light]{--bg:#fff;--text:#172033;--title:#26355f;--muted:#65708b;--muted2:#8992a8;--card:#fff;--composer:#fff;--border:#e1e6f0;--shadow:0 12px 35px #17203312}
html[data-theme=dark]{--bg:#070b20;--text:#f7f8ff;--title:#aab4ff;--muted:#9da7c9;--muted2:#596282;--card:#171d3b;--composer:#151a35;--border:#29335d;--shadow:0 15px 45px #0008}
html[data-theme=purple]{--bg:#f7f5ff;--text:#241f3c;--title:#5b4db7;--muted:#756f91;--muted2:#9891ae;--card:#fff;--composer:#fff;--border:#e2dcff;--shadow:0 12px 35px #6b5cff18}
@media(max-width:700px){.page{padding:22px 20px 110px}.logo{width:48px;height:48px}.brand-name{font-size:21px}.main{padding-top:62px}.main h1{font-size:36px}.desc{font-size:16px;line-height:1.7}.chat{margin-top:54px}.bubble{font-size:16px}}