:root {
  --bg: #ffffff;
  --fg: #1a1a1a;
  --muted: #6b7280;
  --border: #e5e7eb;
  --accent: #2563eb;
  --card-bg: #f9fafb;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1115;
    --fg: #e5e7eb;
    --muted: #9ca3af;
    --border: #2a2e37;
    --accent: #60a5fa;
    --card-bg: #171a21;
  }
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  line-height: 1.7;
}

.container {
  max-width: 860px;
  margin: 0 auto;
  padding: 40px 20px 80px;
}

header.page-header {
  margin-bottom: 32px;
}

header.page-header h1 {
  font-size: 1.8rem;
  margin-bottom: 4px;
}

header.page-header .updated {
  color: var(--muted);
  font-size: 0.9rem;
}

.breadcrumb {
  font-size: 0.9rem;
  color: var(--muted);
  margin-bottom: 24px;
}

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

.breadcrumb a:hover {
  text-decoration: underline;
}

h2 {
  font-size: 1.25rem;
  margin-top: 2.2em;
  border-bottom: 1px solid var(--border);
  padding-bottom: 6px;
}

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

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 16px;
  margin-top: 24px;
}

.card {
  display: block;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 20px;
  text-decoration: none;
  color: var(--fg);
  transition: border-color 0.15s ease;
}

.card:hover {
  border-color: var(--accent);
}

.card h3 {
  margin: 0 0 6px;
  font-size: 1.05rem;
}

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

.doc-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 16px;
}

.doc-links a {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 8px 14px;
  text-decoration: none;
  font-size: 0.92rem;
}

.doc-links a:hover {
  border-color: var(--accent);
}

.placeholder-notice {
  background: var(--card-bg);
  border: 1px dashed var(--border);
  border-radius: 8px;
  padding: 14px 18px;
  color: var(--muted);
  font-size: 0.9rem;
  margin-bottom: 24px;
}

footer.page-footer {
  margin-top: 60px;
  padding-top: 20px;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.85rem;
}