:root{--bg:#fff;--fg:#1a2233;--muted:#5b6578;--line:#e3e7ee;--accent:#1f5fbf}
@media (prefers-color-scheme:dark){:root{--bg:#0f1420;--fg:#e8ecf4;--muted:#9aa6bb;--line:#232b3d;--accent:#6aa3ff}}
*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--fg);font:16px/1.6 system-ui,-apple-system,Segoe UI,Roboto,sans-serif}
.wrap{max-width:760px;margin:0 auto;padding:0 16px}
header{border-bottom:1px solid var(--line)}header .wrap{display:flex;justify-content:space-between;align-items:center;height:56px}
.brand{font-weight:700;color:var(--fg);text-decoration:none}nav a{margin-left:16px;color:var(--muted);text-decoration:none}
a{color:var(--accent)}main{padding:32px 16px 48px}h1{font-size:2rem;line-height:1.2;margin:0 0 12px}h2{font-size:1.2rem;margin:28px 0 6px}
.lead{font-size:1.15rem;color:var(--muted)}.card{border:1px solid var(--line);border-radius:10px;padding:16px;margin:16px 0}
footer{border-top:1px solid var(--line);color:var(--muted);font-size:.9rem;padding:20px 0}