:root{--blue:#2563EB;--blue-d:#1D4ED8;--ink:#0F172A;--muted:#475569;--line:#E2E8F0;--bg:#F8FAFC;--card:#fff}
*{box-sizing:border-box}
body{margin:0;font-family:"Segoe UI",Roboto,Helvetica,Arial,sans-serif;color:var(--ink);background:var(--bg);line-height:1.6}
a{color:var(--blue)}
.wrap{max-width:1040px;margin:0 auto;padding:0 20px}
header.top{background:#fff;border-bottom:1px solid var(--line)}
header.top .wrap{display:flex;align-items:center;justify-content:space-between;height:64px}
.brand{display:flex;align-items:center;gap:10px;font-weight:700;font-size:20px;color:var(--ink);text-decoration:none}
.logo{width:34px;height:34px;border-radius:9px;background:var(--blue);display:grid;place-items:center}
nav a{margin-left:20px;color:var(--muted);text-decoration:none;font-size:15px}
nav a:hover{color:var(--ink)}
.hero{padding:72px 0 56px;text-align:center}
.hero h1{font-size:42px;line-height:1.15;margin:0 0 16px;letter-spacing:-.5px}
.hero p{font-size:19px;color:var(--muted);max-width:680px;margin:0 auto 28px}
.btn{display:inline-block;background:var(--blue);color:#fff;padding:12px 22px;border-radius:10px;text-decoration:none;font-weight:600}
.btn:hover{background:var(--blue-d)}
section{padding:40px 0}
h2{font-size:28px;margin:0 0 20px;letter-spacing:-.3px}
.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:18px}
.card{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:22px}
.card h3{margin:0 0 8px;font-size:17px}
.card p{margin:0;color:var(--muted);font-size:15px}
.note{background:#EFF6FF;border:1px solid #BFDBFE;border-radius:14px;padding:22px 24px}
.note ul{margin:8px 0 0;padding-left:20px}
footer{border-top:1px solid var(--line);background:#fff;margin-top:40px;padding:28px 0;color:var(--muted);font-size:14px}
footer .links a{margin-right:18px}
.doc{background:#fff;border:1px solid var(--line);border-radius:14px;padding:36px 40px;margin:40px auto}
.doc h1{font-size:32px;margin:0 0 4px}
.doc h2{font-size:21px;margin:32px 0 10px}
.doc h3{font-size:17px;margin:20px 0 6px}
.doc .meta{color:var(--muted);margin:0 0 24px}
.doc li{margin:4px 0}
@media (max-width:640px){nav a.hide-sm{display:none}.hero h1{font-size:31px}.doc{padding:24px 20px}nav a{margin-left:12px}}