:root {
  --bg: #f7f8fa;
  --surface: #ffffff;
  --text: #1a1d21;
  --text-muted: #55606b;
  --border: #e3e6ea;
  --accent: #1f6feb;
  --accent-hover: #185ac4;
  --max-width: 760px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1216;
    --surface: #171b21;
    --text: #eef1f4;
    --text-muted: #a3adb8;
    --border: #2a2f37;
    --accent: #5b9bff;
    --accent-hover: #7cadff;
  }
}

* {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.6;
  overflow-x: hidden;
}

.site-header {
  border-bottom: 1px solid var(--border);
  background: var(--surface);
}

.site-header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 18px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}

.brand {
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--text);
  text-decoration: none;
}

nav.site-nav {
  display: flex;
  gap: 18px;
  flex-wrap: wrap;
}

nav.site-nav a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.95rem;
}

nav.site-nav a:hover,
nav.site-nav a:focus {
  color: var(--accent);
}

main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 40px 20px 64px;
}

h1 {
  font-size: 1.8rem;
  margin: 0 0 8px;
}

h2 {
  font-size: 1.2rem;
  margin: 32px 0 10px;
}

p {
  margin: 0 0 14px;
  color: var(--text);
  word-wrap: break-word;
  overflow-wrap: break-word;
}

.subtitle {
  color: var(--text-muted);
  margin-bottom: 32px;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 24px;
  margin-bottom: 20px;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 16px;
  margin: 24px 0;
}

.card-link {
  display: block;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 18px 20px;
  text-decoration: none;
  color: var(--text);
}

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

.card-link strong {
  display: block;
  margin-bottom: 4px;
  font-size: 1.02rem;
}

.card-link span {
  color: var(--text-muted);
  font-size: 0.9rem;
}

.btn {
  display: inline-block;
  background: var(--accent);
  color: #fff;
  text-decoration: none;
  padding: 10px 18px;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.95rem;
}

.btn:hover,
.btn:focus {
  background: var(--accent-hover);
}

.topic {
  border-bottom: 1px solid var(--border);
  padding: 14px 0;
}

.topic:last-child {
  border-bottom: none;
}

.topic h3 {
  margin: 0 0 6px;
  font-size: 1rem;
}

.topic p {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.95rem;
}

.doc-body {
  white-space: pre-wrap;
  font-size: 0.98rem;
}

footer.site-footer {
  border-top: 1px solid var(--border);
  margin-top: 40px;
}

.site-footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 24px 20px 40px;
  color: var(--text-muted);
  font-size: 0.85rem;
  display: flex;
  flex-wrap: wrap;
  gap: 8px 16px;
}

.site-footer-inner a {
  color: var(--text-muted);
}

img, svg {
  max-width: 100%;
}

@media (max-width: 480px) {
  h1 {
    font-size: 1.5rem;
  }
  main {
    padding: 28px 16px 48px;
  }
}