:root {
  color-scheme: light dark;
  --fg: #1f2328;
  --bg: #ffffff;
  --link: #0b5cad;
}
@media (prefers-color-scheme: dark) {
  :root { --fg: #e6e6e6; --bg: #16181c; --link: #7cb7ff; }
}
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 17px/1.6 system-ui, -apple-system, "Segoe UI", sans-serif;
}
main { max-width: 40rem; margin: 3rem auto; padding: 0 1rem; }
h1 { font-size: 1.6rem; line-height: 1.3; }
h2 { font-size: 1.15rem; margin-top: 2rem; }
a { color: var(--link); }