:root {
  --fg: #111;
  --muted: #666;
  --link: #1a4fb8;
  --bg: #fdfdfc;
  --rule: #e5e5e3;
}

@media (prefers-color-scheme: dark) {
  :root {
    --fg: #eceae6;
    --muted: #9a9a96;
    --link: #8ab4ff;
    --bg: #16161a;
    --rule: #2a2a2e;
  }
}

* {
  box-sizing: border-box;
}

html {
  font-size: 18px;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: Georgia, "Hiragino Mincho ProN", "Yu Mincho", serif;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

main {
  max-width: 38rem;
  margin: 0 auto;
  padding: 4rem 1.5rem 6rem;
}

header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

h1 {
  font-size: 2.25rem;
  margin: 0;
  letter-spacing: -0.01em;
}

h2 {
  font-size: 1.25rem;
  margin: 2.5rem 0 0.75rem;
  padding-bottom: 0.25rem;
  border-bottom: 1px solid var(--rule);
}

.intro {
  margin: 0 0 1rem;
}

.lang a {
  font-family: system-ui, -apple-system, sans-serif;
  font-size: 0.9rem;
  color: var(--muted);
  text-decoration: none;
}

.lang a:hover {
  color: var(--fg);
  text-decoration: underline;
}

ul {
  padding-left: 1.25rem;
  margin: 0;
}

li {
  margin: 0.35rem 0;
}

a {
  color: var(--link);
  text-decoration: underline;
  text-underline-offset: 2px;
}

a:hover {
  text-decoration-thickness: 2px;
}