:root{--bg:#fbfbfd;--fg:#1d1d1f;--muted:#55595f;--card:#fff;--line:#e3e4e8;--accent:#2457d6;--accent-fg:#fff;--mark:#e6eeff;--soft:#f2f4f8}
@media (prefers-color-scheme:dark){:root{--bg:#0f1115;--fg:#eceef2;--muted:#a7adb7;--card:#171a20;--line:#2a2f38;--accent:#7aa2ff;--accent-fg:#0b1020;--mark:#1f2c4d;--soft:#141821}}
*{box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}}
body{margin:0;background:var(--bg);color:var(--fg);font:16px/1.65 -apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei","Noto Sans CJK SC",Roboto,"Helvetica Neue",Arial,sans-serif}
html[data-lang="zh"] [lang="en"],html[data-lang="en"] [lang="zh"]{display:none!important}
a{color:var(--accent)}
a:focus-visible,button:focus-visible,summary:focus-visible,.table-scroll:focus-visible{outline:3px solid var(--accent);outline-offset:3px;border-radius:6px}
.wrap{max-width:1120px;margin:0 auto;padding:0 24px}
.narrow{max-width:780px}
.skip{position:absolute;left:-999px;top:8px;background:var(--accent);color:var(--accent-fg);padding:8px 14px;border-radius:8px;z-index:10}
.skip:focus{left:8px}
.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
.top{position:sticky;top:0;z-index:5;background:color-mix(in srgb,var(--bg) 88%,transparent);backdrop-filter:saturate(1.4) blur(10px);-webkit-backdrop-filter:saturate(1.4) blur(10px);border-bottom:1px solid var(--line)}
.bar{display:flex;align-items:center;gap:20px;height:60px}
.brand{display:flex;align-items:center;gap:10px;font-weight:700;font-size:18px;color:var(--fg);text-decoration:none}
nav{display:flex;gap:18px;margin-left:auto}
nav a{color:var(--muted);text-decoration:none;font-size:15px}
nav a:hover{color:var(--fg)}
.lang{font:inherit;font-size:14px;padding:6px 14px;border-radius:999px;border:1px solid var(--line);background:var(--card);color:var(--fg);cursor:pointer;min-height:36px}
.lang:hover{border-color:var(--accent)}
section{padding:72px 0;border-bottom:1px solid var(--line)}
.hero{padding:88px 0 56px;border:0;text-align:center}
.eyebrow{color:var(--accent);font-weight:600;font-size:14px;letter-spacing:.04em;margin:0 0 14px}
h1{font-size:clamp(30px,5.2vw,56px);line-height:1.15;letter-spacing:-.02em;margin:0 0 18px}
h2{font-size:clamp(24px,3.2vw,34px);line-height:1.25;margin:0 0 14px;letter-spacing:-.01em}
h3{font-size:18px;line-height:1.4;margin:0 0 8px}
.lead{font-size:clamp(17px,2vw,20px);color:var(--muted);max-width:680px;margin:0 auto 30px}
.sample{margin:0 auto 30px;max-width:720px;background:var(--card);border:1px solid var(--line);border-radius:16px;padding:20px 24px;text-align:left}
.sample figcaption{font-size:13px;color:var(--muted)}
.sample blockquote{margin:8px 0;font-size:clamp(18px,2.4vw,24px);font-weight:600;line-height:1.5}
mark{background:var(--mark);color:inherit;padding:0 4px;border-radius:4px}
.note{margin:0;color:var(--muted);font-size:15px}
.cta{display:flex;gap:12px;justify-content:center;flex-wrap:wrap;margin-bottom:14px}
.btn{display:inline-flex;align-items:center;min-height:46px;padding:0 22px;border-radius:12px;border:1px solid var(--line);background:var(--card);color:var(--fg);text-decoration:none;font-weight:600}
.btn.primary{background:var(--accent);border-color:var(--accent);color:var(--accent-fg)}
.btn:hover{filter:brightness(1.06)}
.small{font-size:14px;color:var(--muted);margin:0}
.demo{padding:0 0 72px}
.poster{aspect-ratio:16/9;max-width:900px;margin:0 auto;border-radius:20px;border:2px dashed var(--line);background:linear-gradient(135deg,var(--soft),var(--card));display:grid;place-items:center;text-align:center;padding:24px}
.play{width:72px;height:72px;border-radius:50%;background:var(--accent);margin:0 auto 16px;position:relative;opacity:.9}
.play::after{content:"";position:absolute;left:29px;top:22px;border-left:22px solid var(--accent-fg);border-top:14px solid transparent;border-bottom:14px solid transparent}
.poster-title{font-size:22px;font-weight:700;margin:0 0 6px}
.poster-sub{color:var(--muted);margin:0 auto;max-width:520px;font-size:15px}
.intro{color:var(--muted);max-width:760px;margin:0 0 32px}
.cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(300px,1fr));gap:18px}
.card{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:22px 24px}
.card p{margin:0 0 10px}
.card ul{margin:0;padding-left:20px}
.fine{font-size:14px;color:var(--muted)}
.card .fine{margin:0}
.two{display:grid;grid-template-columns:1.4fr 1fr;gap:40px;align-items:start}
.two h3{margin-top:22px}
.steps li,.perm li{margin-bottom:8px}
code{font:14px ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;background:var(--soft);padding:1px 6px;border-radius:5px}
.limits{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:22px 24px;position:sticky;top:80px}
.limits h3{margin-top:0}
.limits ul{padding-left:18px;margin:0 0 12px}
.limits li{margin-bottom:10px;font-size:15px}
.table-scroll{overflow-x:auto;border:1px solid var(--line);border-radius:14px;background:var(--card)}
table{border-collapse:collapse;width:100%;min-width:760px;font-size:15px}
th,td{text-align:left;padding:12px 14px;border-bottom:1px solid var(--line);vertical-align:top}
thead th{font-size:13px;color:var(--muted);font-weight:600;background:var(--soft)}
tbody tr:last-child th,tbody tr:last-child td{border-bottom:0}
tr.me{background:var(--mark)}
td.unk{color:var(--muted);font-style:italic}
details{border:1px solid var(--line);border-radius:12px;background:var(--card);margin-bottom:10px;padding:0 18px}
summary{cursor:pointer;font-weight:600;padding:14px 0;list-style-position:outside}
details p{margin:0 0 16px;color:var(--fg)}
footer{padding:40px 0 56px}
.foot p{margin:0 0 8px;color:var(--muted);font-size:14px}
@media (max-width:820px){.two{grid-template-columns:1fr}.limits{position:static}nav{display:none}.lang{margin-left:auto}section{padding:56px 0}.hero{padding:56px 0 40px}.hero h1 br{display:none}}
@media (max-width:420px){.wrap{padding:0 18px}.cards{grid-template-columns:1fr}.btn{width:100%;justify-content:center}}
h1,h2,.lead,.poster-sub{text-wrap:balance}
td:nth-child(4){white-space:nowrap}