:root{
  --bg:#0c1116;
  --bg-soft:#131a22;
  --panel:#151d26;
  --line:#233040;
  --fg:#e8eef5;
  --fg-dim:#94a6b8;
  --accent:#4da3c7;
  --accent-warm:#d9ae5f;
  --radius:14px;
  --maxw:1080px;
}
*{box-sizing:border-box;margin:0;padding:0;}
html{-webkit-text-size-adjust:100%;}
body{
  background:var(--bg);
  color:var(--fg);
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  line-height:1.75;
  font-size:16px;
  -webkit-font-smoothing:antialiased;
}
a{color:inherit;text-decoration:none;}
.container{max-width:var(--maxw);margin:0 auto;padding:0 24px;}

/* header */
.site-header{
  position:sticky;top:0;z-index:50;
  background:rgba(12,17,22,.88);
  backdrop-filter:blur(12px);
  border-bottom:1px solid var(--line);
}
.header-inner{display:flex;align-items:center;justify-content:space-between;height:66px;gap:16px;}
.brand{display:flex;align-items:center;gap:10px;font-weight:700;letter-spacing:.3px;}
.brand-mark{
  width:32px;height:32px;flex:0 0 32px;
  display:grid;place-items:center;
  border-radius:9px;
  background:linear-gradient(135deg,#2b6d8a,#17475c);
  color:#dff1f8;font-size:16px;
  border:1px solid #356d86;
}
.brand-text{font-size:16px;}
.site-nav{display:flex;gap:4px;}
.site-nav a{
  padding:8px 14px;border-radius:9px;
  color:var(--fg-dim);font-size:15px;
  transition:background .18s,color .18s;
}
.site-nav a:hover{color:var(--fg);background:#1b242e;}
.site-nav a.active{color:#cfe9f5;background:#1d2a35;}

/* hero */
.hero{padding:88px 0 72px;border-bottom:1px solid var(--line);}
.hero-eyebrow{
  font-size:13px;letter-spacing:2.6px;text-transform:uppercase;
  color:var(--accent);margin-bottom:18px;font-weight:600;
}
.hero h1{font-size:clamp(30px,5vw,48px);line-height:1.32;font-weight:800;letter-spacing:-.5px;}
.hero-sub{margin-top:22px;max-width:620px;color:var(--fg-dim);font-size:17px;}
.hero-actions{display:flex;gap:12px;margin-top:34px;flex-wrap:wrap;}
.btn{
  display:inline-block;padding:12px 24px;border-radius:10px;
  font-size:15px;font-weight:600;transition:transform .16s,background .18s,border-color .18s;
}
.btn:active{transform:translateY(1px);}
.btn-primary{background:var(--accent);color:#06202b;}
.btn-primary:hover{background:#5cb3d6;}
.btn-ghost{border:1px solid var(--line);color:var(--fg-dim);}
.btn-ghost:hover{border-color:#3a5064;color:var(--fg);}

/* sections */
.section{padding:64px 0;}
.section-title{
  font-size:22px;font-weight:700;margin-bottom:30px;
  padding-left:14px;border-left:3px solid var(--accent);
}
.grid{display:grid;gap:20px;}
.grid-3{grid-template-columns:repeat(3,1fr);}
.card{
  background:var(--panel);border:1px solid var(--line);
  border-radius:var(--radius);padding:26px;
  transition:border-color .2s,transform .2s;
}
.card:hover{border-color:#33475c;transform:translateY(-2px);}
.card-icon{font-size:26px;margin-bottom:14px;}
.card h3{font-size:17px;font-weight:700;margin-bottom:10px;}
.card p{color:var(--fg-dim);font-size:15px;}

.highlight-box{
  background:linear-gradient(135deg,#141d26,#111820);
  border:1px solid var(--line);border-left:3px solid var(--accent-warm);
  border-radius:var(--radius);padding:30px;
}
.highlight-label{
  font-size:12px;letter-spacing:2px;text-transform:uppercase;
  color:var(--accent-warm);font-weight:700;margin-bottom:12px;
}
.highlight-box h3{font-size:20px;font-weight:700;margin-bottom:14px;}
.highlight-box p{color:var(--fg-dim);font-size:15px;}
.link-arrow{display:inline-block;margin-top:18px;color:var(--accent);font-weight:600;font-size:15px;}
.link-arrow:hover{text-decoration:underline;}

/* prose pages */
.page-head{padding:64px 0 8px;}
.page-head h1{font-size:clamp(26px,4vw,38px);font-weight:800;letter-spacing:-.4px;}
.page-head p.lead{margin-top:16px;color:var(--fg-dim);max-width:680px;font-size:17px;}
.prose{max-width:760px;padding-bottom:56px;}
.prose h2{font-size:19px;font-weight:700;margin:38px 0 14px;color:#dfeaf3;}
.prose h2:first-child{margin-top:8px;}
.prose p{color:var(--fg-dim);margin:12px 0;font-size:15.5px;}
.prose ul{margin:12px 0 12px 20px;color:var(--fg-dim);font-size:15.5px;}
.prose li{margin:7px 0;}
.prose strong{color:#dbe6ef;}
.prose code{
  background:#1b2530;border:1px solid var(--line);
  padding:2px 7px;border-radius:6px;font-size:14px;
  font-family:ui-monospace,SFMono-Regular,Consolas,monospace;color:#9fd3e8;
}
.spec-table{width:100%;border-collapse:collapse;margin:18px 0;font-size:15px;}
.spec-table th,.spec-table td{
  text-align:left;padding:11px 14px;border-bottom:1px solid var(--line);
}
.spec-table th{color:#cbdae6;font-weight:600;width:38%;}
.spec-table td{color:var(--fg-dim);}

/* footer */
.site-footer{
  border-top:1px solid var(--line);
  background:#0a0f14;
  padding:38px 0;margin-top:40px;
}
.footer-inner{display:flex;justify-content:space-between;gap:24px;flex-wrap:wrap;align-items:flex-end;}
.footer-title{font-weight:700;font-size:15px;}
.footer-desc{color:var(--fg-dim);font-size:14px;margin-top:6px;}
.footer-meta{text-align:right;}
.footer-meta a{color:var(--accent);font-size:14px;}
.footer-meta a:hover{text-decoration:underline;}
.footer-copy{color:#63758a;font-size:13px;margin-top:6px;}

/* responsive */
@media(max-width:820px){
  .grid-3{grid-template-columns:1fr;}
  .hero{padding:60px 0 52px;}
  .section{padding:48px 0;}
  .header-inner{height:60px;}
  .brand-text{font-size:15px;}
  .site-nav a{padding:7px 10px;font-size:14px;}
  .footer-inner{flex-direction:column;align-items:flex-start;}
  .footer-meta{text-align:left;}
}