:root {
  color-scheme: light dark;
  --fg: #1b1b1f;
  --bg: #fafaf9;
  --muted: #6b6b73;
}
@media (prefers-color-scheme: dark) {
  :root { --fg: #ececef; --bg: #151517; --muted: #9a9aa3; }
}
body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
  line-height: 1.6;
  color: var(--fg);
  background: var(--bg);
}
main { max-width: 42rem; margin: 0 auto; padding: 4rem 1rem; }
.muted { color: var(--muted); }