:root{--bg:#f9f8f6;--panel:#fff;--soft:#f3f1ed;--line:#e9e6e0;--text:#141414;--muted:#6f6b64;--faint:#a19d95;--violet:#6d4aff;--violet-soft:#f1ebff;--mark:#d8c8ff;--max:1120px;--font:Inter,-apple-system,BlinkMacSystemFont,"PingFang SC","Hiragino Sans GB","Microsoft YaHei","Segoe UI",sans-serif}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;scroll-padding-top:80px}
body{background:var(--bg);color:var(--text);font:16px/1.65 var(--font);-webkit-font-smoothing:antialiased;overflow-x:hidden}
a{color:inherit;text-decoration:none}
ul,ol{list-style:none}
img{display:block}
mark{background:linear-gradient(transparent 60%,var(--mark) 60%);color:inherit;padding:0 .06em}

.nav{position:sticky;top:0;z-index:10;display:flex;align-items:center;gap:24px;padding:14px max(24px,calc((100% - var(--max))/2 + 24px));background:rgba(249,248,246,.85);backdrop-filter:blur(12px);border-bottom:1px solid var(--line)}
.brand{display:flex;align-items:center;gap:10px;font-weight:700;font-size:18px;letter-spacing:-.2px}
.brand img{width:30px;height:30px;border-radius:9px}
.nav nav{display:flex;gap:26px;margin-left:auto;color:var(--muted);font-size:15px}
.nav nav a:hover{color:var(--text)}
.lang{display:flex;padding:3px;border-radius:999px;border:1px solid var(--line);background:#fff;cursor:pointer;font:600 12px var(--font)}
.lang span{padding:3px 9px;border-radius:999px;color:var(--muted)}
html[data-lang=zh] .lang [data-l=zh],html[data-lang=en] .lang [data-l=en]{background:var(--text);color:#fff}

.btn{display:inline-flex;align-items:center;justify-content:center;padding:13px 26px;border-radius:999px;background:var(--text);color:#fff;font-weight:600;transition:transform .15s,background .2s}
.btn:hover{background:#000;transform:translateY(-1px)}
.btn.small{padding:8px 18px;font-size:14px}
.btn.ghost{background:#fff;color:var(--text);border:1px solid var(--line)}
.btn.ghost:hover{border-color:var(--text);background:#fff}

.hero{max-width:1040px;margin:0 auto;padding:96px 24px 40px;text-align:center;display:grid;justify-items:center}
h1{font-size:64px;line-height:1.12;letter-spacing:-1.5px;font-weight:700;max-width:980px}
html[data-lang=zh] h1{letter-spacing:-.5px}
@media (min-width:901px){html[data-lang=en] h1{font-size:56px}}
h1 mark{white-space:nowrap}
.lead{color:var(--muted);font-size:20px;max-width:640px;margin-top:20px}
.cta{display:flex;gap:12px;flex-wrap:wrap;justify-content:center;margin-top:34px}
.works{margin-top:22px;color:var(--faint);font-size:14px}

.demo{max-width:var(--max);margin:0 auto;padding:24px 24px 0}
.frame{padding:8px;border-radius:26px;background:#fff;border:1px solid var(--line);box-shadow:0 30px 70px rgba(20,20,20,.1)}
.frame video{display:block;width:100%;aspect-ratio:16/9;border-radius:19px;background:var(--bg)}

.section{max-width:var(--max);margin:0 auto;padding:120px 24px 0}
.eyebrow{text-align:center;color:var(--violet);font-weight:600;font-size:14px;margin-bottom:10px}
.eyebrow.left,.sub.left{text-align:left;margin-left:0}
h2{font-size:42px;line-height:1.22;letter-spacing:-.8px;font-weight:700;text-align:center}
html[data-lang=zh] h2{letter-spacing:-.3px}
.sub{max-width:680px;margin:16px auto 0;text-align:center;color:var(--muted);font-size:17px}
h3{font-size:20px;letter-spacing:-.2px;margin-bottom:8px}

.pillars{display:grid;grid-template-columns:repeat(3,1fr);gap:20px;margin-top:48px}
.pillar{padding:30px 28px;border-radius:24px;background:#fff;border:1px solid var(--line)}
.pillar .num{display:block;font:600 14px ui-monospace,Menlo,monospace;color:var(--violet);margin-bottom:28px}
.pillar h3{font-size:26px}
.pillar p,.tile p,.step p{color:var(--muted);font-size:15px}

.cases{display:grid;grid-template-columns:repeat(3,1fr);gap:20px;margin-top:44px}
.case{display:flex;flex-direction:column;padding:26px;border-radius:24px;background:#fff;border:1px solid var(--line)}
.dept{align-self:flex-start;padding:3px 12px;border-radius:999px;background:var(--violet-soft);color:var(--violet);font-size:13px;font-weight:600}
.ask{flex:1;margin:18px 0 22px;font-size:18px;line-height:1.55}
.who{padding-top:14px;border-top:1px solid var(--line);color:var(--muted);font-size:14px}
.who b{color:var(--text);font-weight:600}
.note{margin-top:16px;text-align:center;color:var(--faint);font-size:13px}

.split{display:grid;grid-template-columns:1fr 1fr;gap:56px;align-items:center}
.split h2{text-align:left}
.checks{margin-top:24px;display:grid;gap:12px}
.checks li{position:relative;padding-left:30px}
.checks li::before{content:"✓";position:absolute;left:0;top:2px;display:grid;place-items:center;width:20px;height:20px;border-radius:50%;background:var(--violet-soft);color:var(--violet);font-size:12px;font-weight:700}
.mock{padding:32px 26px;border-radius:24px;background:#fff;border:1px solid var(--line);display:grid;justify-items:center;gap:22px}
.node{padding:9px 18px;border-radius:12px;background:var(--soft);font-size:15px}
.node.root{background:var(--text);color:#fff;font-weight:600}
.node.hot{background:var(--violet-soft);color:var(--violet);font-weight:600}
.branch{display:flex;gap:12px}
.proposal{width:100%;padding:16px;border-radius:16px;border:1px dashed #d8d4cc;font-size:14px}
.badge{display:inline-block;margin-right:8px;padding:1px 10px;border-radius:999px;background:#fff6e6;color:#92400e;font-size:12px}
.acts{display:flex;gap:8px;margin-top:12px}
.acts span{padding:5px 14px;border-radius:999px;border:1px solid var(--line);font-size:13px}
.acts .ok{background:var(--text);color:#fff;border-color:var(--text)}

.grid4{display:grid;grid-template-columns:repeat(4,1fr);gap:16px;margin-top:44px}
.tile{padding:24px;border-radius:22px;background:#fff;border:1px solid var(--line)}
.tile h3{font-size:17px}
.steps{display:grid;grid-template-columns:repeat(3,1fr);gap:20px;margin-top:44px}
.step{padding:28px;border-radius:24px;background:#fff;border:1px solid var(--line)}
.step .n{display:grid;place-items:center;width:34px;height:34px;border-radius:50%;background:var(--violet-soft);color:var(--violet);font-weight:700;margin-bottom:18px}

.final{max-width:var(--max);margin:120px auto 0;padding:72px 24px;text-align:center;display:grid;justify-items:center;gap:26px;border-radius:32px;background:var(--text);color:#fff}
.final img{width:64px;height:64px;border-radius:18px}
.final .btn{background:#fff;color:var(--text)}
footer{max-width:var(--max);margin:0 auto;padding:32px 24px 44px;display:flex;justify-content:space-between;color:var(--muted);font-size:14px}

@media (max-width:900px){
  .nav nav{display:none}
  .lang{margin-left:auto}
  h1{font-size:42px}
  h2{font-size:30px}
  .hero{padding-top:56px}
  .pillars,.cases,.steps,.split{grid-template-columns:1fr}
  .grid4{grid-template-columns:1fr 1fr}
  .final{margin-left:16px;margin-right:16px}
}
@media (max-width:520px){
  .nav{gap:12px;padding:12px 16px}
  .brand{font-size:16px}
  .hero,.section,.demo{padding-left:16px;padding-right:16px}
  h1{font-size:32px}
  .lead{font-size:17px}
  .grid4{grid-template-columns:1fr}
}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}.btn{transition:none}}