:root {
  --bg: #ffffff;
  --fg: #1a1a1a;
  --muted: #666666;
  --accent: #2563eb;
  --border: #e5e5e5;
  --card: #f8f8f8;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #121212;
    --fg: #e8e8e8;
    --muted: #9a9a9a;
    --accent: #7aa2ff;
    --border: #2a2a2a;
    --card: #1c1c1c;
  }
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Helvetica Neue",
    "Hiragino Kaku Gothic ProN", "Hiragino Sans", Meiryo, sans-serif;
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
}

.container {
  max-width: 720px;
  margin: 0 auto;
  padding: 2.5rem 1.25rem 4rem;
}

header.site-header {
  border-bottom: 1px solid var(--border);
  padding-bottom: 1.25rem;
  margin-bottom: 2rem;
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.site-name {
  font-size: 1rem;
  font-weight: 600;
  color: var(--fg);
  text-decoration: none;
}

.lang-switch {
  font-size: 0.85rem;
}

.lang-switch a {
  color: var(--accent);
  text-decoration: none;
}

.lang-switch a:hover {
  text-decoration: underline;
}

h1 {
  font-size: 1.6rem;
  line-height: 1.4;
  margin-bottom: 0.5rem;
}

.updated {
  color: var(--muted);
  font-size: 0.85rem;
  margin-bottom: 2rem;
}

h2 {
  font-size: 1.15rem;
  margin-top: 2.25rem;
  margin-bottom: 0.75rem;
  padding-top: 0.5rem;
}

p, ul, ol {
  margin-bottom: 1rem;
}

ul, ol {
  padding-left: 1.5rem;
}

a {
  color: var(--accent);
}

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.25rem 1.5rem;
  margin-bottom: 1rem;
}

.card a.title {
  font-weight: 600;
  font-size: 1.05rem;
  text-decoration: none;
}

.card p {
  margin: 0.25rem 0 0;
  color: var(--muted);
  font-size: 0.9rem;
}

footer.site-footer {
  margin-top: 3.5rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.85rem;
}