:root { color-scheme: light dark; --fg: #1b1b1b; --bg: #fafafa; --link: #1a5fb4; }
@media (prefers-color-scheme: dark) { :root { --fg: #e6e6e6; --bg: #161616; --link: #8ab4f8; } }
body { margin: 0; background: var(--bg); color: var(--fg);
  font: 17px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif; }
main { max-width: 42rem; margin: 0 auto; padding: 2.5rem 1rem 4rem; }
h1 { font-size: 1.8rem; margin: 0.5rem 0 1rem; }
h2 { font-size: 1.15rem; margin-top: 2rem; }
a { color: var(--link); }