:root {
  --bg: #ffffff;
  --fg: #1a1a1a;
  --muted: #666666;
  --border: #eaeaea;
  --max-width: 720px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111111;
    --fg: #f2f2f2;
    --muted: #999999;
    --border: #2a2a2a;
  }
}

* {
  box-sizing: border-box;
}

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

.wrap {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

.site-header {
  border-bottom: 1px solid var(--border);
  padding: 20px 0;
}

.site-header .wrap {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.brand {
  font-weight: 600;
}

.site-header nav a {
  margin-left: 20px;
  color: var(--muted);
  text-decoration: none;
  font-size: 0.95rem;
}

.site-header nav a:hover {
  color: var(--fg);
}

.hero {
  padding: 80px 24px 40px;
}

.hero h1 {
  font-size: 2.2rem;
  margin: 0 0 8px;
}

.subtitle {
  color: var(--muted);
  font-size: 1.1rem;
  margin: 0;
}

.section {
  padding: 40px 24px;
  border-top: 1px solid var(--border);
}

.section h2 {
  font-size: 1.3rem;
  margin: 0 0 20px;
}

.grid {
  display: grid;
  gap: 16px;
}

.card {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 18px;
}

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

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

footer {
  padding: 30px 24px 50px;
  color: var(--muted);
  font-size: 0.9rem;
}