:root { color-scheme: light dark; --fg: #1d1d1f; --muted: #6e6e73; --bg: #ffffff; --link: #0066cc; }
@media (prefers-color-scheme: dark) {
  :root { --fg: #f5f5f7; --muted: #a1a1a6; --bg: #000000; --link: #2997ff; }
}
body { margin: 0; background: var(--bg); color: var(--fg); font: 17px/1.55 -apple-system, BlinkMacSystemFont, "Helvetica Neue", sans-serif; }
main { max-width: 680px; margin: 0 auto; padding: 48px 16px 64px; }
h1 { font-size: 34px; margin: 8px 0 4px; }
h2 { font-size: 21px; margin-top: 32px; }
h3 { font-size: 17px; margin-top: 24px; }
a { color: var(--link); }
.muted { color: var(--muted); }
.lead { font-size: 21px; color: var(--muted); }