:root{--bg:#fff;--fg:#111827;--muted:#6b7280;--accent:#2563eb;--card:#f3f4f6}
@media(prefers-color-scheme:dark){:root{--bg:#0b0f17;--fg:#e5e7eb;--muted:#9ca3af;--accent:#60a5fa;--card:#161c28}}
*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--fg);font:16px/1.6 system-ui,sans-serif}
main,header,footer{max-width:760px;margin:0 auto;padding:16px}
header{display:flex;justify-content:space-between;align-items:center}
a{color:var(--accent)}h1{font-size:2.2rem;line-height:1.2}
.card{background:var(--card);border-radius:12px;padding:16px;margin:12px 0}
.muted{color:var(--muted);font-size:.9rem}