:root { color-scheme: light dark; --fg: #1d1d1f; --muted: #6e6e73; --bg: #fff; --link: #0066cc; }
@media (prefers-color-scheme: dark) { :root { --fg: #f5f5f7; --muted: #a1a1a6; --bg: #1c1c1e; --link: #4da3ff; } }
body { margin: 0; background: var(--bg); color: var(--fg);
  font: 16px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif; }
main { max-width: 640px; margin: 0 auto; padding: 48px 16px; }
h1 { font-size: 28px; margin: 0 0 4px; }
h2 { font-size: 18px; margin: 28px 0 4px; }
.sub { color: var(--muted); margin: 0 0 24px; }
a { color: var(--link); }
footer { margin-top: 40px; color: var(--muted); font-size: 14px; }