:root{--bg:#f7f8fa;--card:#fff;--ink:#1c2430;--muted:#5b6675;--accent:#2f6fed;--line:#e3e7ee}
@media(prefers-color-scheme:dark){:root{--bg:#10141a;--card:#171c24;--ink:#e8ecf2;--muted:#9aa5b5;--accent:#6c9bff;--line:#262d38}}
*{box-sizing:border-box}
body{margin:0;background:var(--bg);color:var(--ink);font:16px/1.65 system-ui,-apple-system,"Segoe UI",Roboto,sans-serif}
header,main,footer{max-width:720px;margin:0 auto;padding:0 20px}
header{padding-top:40px;display:flex;align-items:center;gap:12px}
.logo{width:36px;height:36px;border-radius:10px;background:linear-gradient(135deg,#2f6fed,#7c5cff);display:grid;place-items:center;color:#fff;font-weight:700}
.brand{font-weight:650;font-size:1.05rem;letter-spacing:.01em}
nav{margin-left:auto;font-size:.92rem}
nav a{color:var(--muted);text-decoration:none;margin-left:16px}
nav a:hover{color:var(--accent)}
main{padding-top:28px;padding-bottom:40px}
.card{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:32px 30px;margin-bottom:20px}
h1{font-size:1.85rem;line-height:1.25;margin:0 0 12px}
h2{font-size:1.1rem;margin:28px 0 6px}
p,li{color:var(--ink)}
.lead{color:var(--muted);font-size:1.08rem}
.muted{color:var(--muted);font-size:.9rem}
a{color:var(--accent)}
ul{padding-left:20px}
footer{padding-bottom:48px;color:var(--muted);font-size:.88rem}
@media(max-width:520px){.card{padding:24px 20px}h1{font-size:1.5rem}}