:root{color-scheme:light dark;--bg:#f3f7ff;--card:#fff;--text:#14163a;--muted:#555a85;--tint:#2a22cc;--border:#d9e0f5}
@media (prefers-color-scheme:dark){:root{--bg:#0b0e24;--card:#141838;--text:#eef0ff;--muted:#a9b0dc;--tint:#9db0ff;--border:#262c5a}}
*{box-sizing:border-box}
body{margin:0;background:var(--bg);color:var(--text);font:17px/1.6 system-ui,-apple-system,"Segoe UI",Roboto,sans-serif}
main{max-width:720px;margin:0 auto;padding:32px 20px 64px}
.card{background:var(--card);border:1px solid var(--border);border-radius:16px;padding:24px 28px}
h1{font-size:2rem;line-height:1.2;margin:0 0 4px}
h2{font-size:1.25rem;margin:2rem 0 .25rem}
p,li{margin:.6rem 0}
.muted{color:var(--muted)}
a{color:var(--tint)}
nav{display:flex;gap:16px;margin-bottom:20px;font-size:.95rem;flex-wrap:wrap}
footer{margin-top:24px;font-size:.9rem;color:var(--muted)}