:root {
  color-scheme: light dark;
  --bg: #ffffff;
  --fg: #1b1f33;
  --muted: #555b70;
  --link: #2b3a7a;
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #0e1333; --fg: #eef0f8; --muted: #b6bbd0; --link: #ffc56b; }
}
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 17px/1.55 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}
main { max-width: 640px; margin: 0 auto; padding: 48px 16px 64px; }
.icon { border-radius: 22%; }
h1 { font-size: 2rem; line-height: 1.2; margin: 16px 0; }
h2 { font-size: 1.25rem; margin-top: 2em; }
p, li { color: var(--fg); }
a { color: var(--link); }
nav { margin-top: 32px; color: var(--muted); }