:root {
  --bg: #fafafa;
  --fg: #1f2328;
  --muted: #656d76;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0d1117;
    --fg: #e6edf3;
    --muted: #8d96a0;
  }
}
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: system-ui, -apple-system, "Hiragino Sans", "Noto Sans JP", sans-serif;
  line-height: 1.7;
}
main {
  max-width: 36rem;
  margin: 0 auto;
  padding: 3rem 1rem;
}
h1 {
  font-size: 1.6rem;
  letter-spacing: 0.04em;
}
.note {
  color: var(--muted);
  font-size: 0.9rem;
}