:root {
  --bg: #fdfdfd;
  --fg: #1a1a1a;
  --muted: #666;
  --border: #e5e5e5;
  --accent: #0066cc;
  --max-width: 720px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0d0d0d;
    --fg: #ededed;
    --muted: #999;
    --border: #2a2a2a;
    --accent: #6aa3ff;
  }
}

* { box-sizing: border-box; }

html { font-size: 16px; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Sans",
    "Noto Sans CJK JP", "Noto Sans CJK TC", "PingFang TC", sans-serif;
  line-height: 1.7;
  background: var(--bg);
  color: var(--fg);
  -webkit-text-size-adjust: 100%;
}

.wrap {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1.5rem 1.25rem 3rem;
}

.site-header {
  padding: 0.75rem 0 1rem;
  border-bottom: 1px solid var(--border);
  margin-bottom: 2rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1.5rem;
  align-items: baseline;
  justify-content: space-between;
}

.brand {
  font-weight: 600;
  font-size: 1.05rem;
  text-decoration: none;
  color: var(--fg);
}

.lang-nav {
  font-size: 0.9rem;
  color: var(--muted);
}

.lang-nav a {
  color: var(--muted);
  text-decoration: none;
  margin-left: 0.75rem;
}

.lang-nav a:first-child { margin-left: 0; }

.lang-nav a[aria-current="page"] {
  color: var(--fg);
  font-weight: 600;
}

.lang-nav a:not([aria-current]):hover {
  color: var(--accent);
  text-decoration: underline;
}

main h1 {
  font-size: 1.7rem;
  line-height: 1.3;
  margin: 0 0 0.5rem;
}

main h2 {
  font-size: 1.2rem;
  margin: 2rem 0 0.5rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
}

main h3 {
  font-size: 1.05rem;
  margin: 1.5rem 0 0.25rem;
}

main p { margin: 0.75rem 0; }

main ul { padding-left: 1.25rem; }

main li { margin: 0.25rem 0; }

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

main code {
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 0.92em;
  background: var(--border);
  padding: 0.05rem 0.35rem;
  border-radius: 3px;
}

.meta {
  color: var(--muted);
  font-size: 0.875rem;
  margin-bottom: 1.5rem;
}

.site-footer {
  margin-top: 3rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  font-size: 0.875rem;
  color: var(--muted);
}

.site-footer p { margin: 0.4rem 0; }
.site-footer a { color: var(--muted); }
.site-footer a:hover { color: var(--accent); }

.lang-picker {
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  margin: 2rem 0;
}

.lang-card {
  padding: 1rem 1.25rem;
  border: 1px solid var(--border);
  border-radius: 0.5rem;
}

.lang-card h2 {
  margin: 0 0 0.5rem;
  font-size: 1.05rem;
  border: none;
  padding: 0;
}

.lang-card ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.lang-card li { margin: 0.25rem 0; }

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

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

@media print {
  .site-header .lang-nav,
  .site-footer { display: none; }
  body { color: black; background: white; }
}