:root {
  --bg: #ffffff;
  --fg: #1c1c1e;
  --muted: #6e6e73;
  --accent: #0a84ff;
  --border: #e5e5ea;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #1c1c1e;
    --fg: #f2f2f7;
    --muted: #98989d;
    --accent: #0a84ff;
    --border: #2c2c2e;
  }
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  font-size: 16px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  -webkit-text-size-adjust: 100%;
}

main {
  max-width: 720px;
  margin: 0 auto;
  padding: 48px 24px 96px;
}

header {
  border-bottom: 1px solid var(--border);
  padding-bottom: 16px;
  margin-bottom: 32px;
}

header .brand {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--fg);
  text-decoration: none;
}

header nav {
  margin-top: 8px;
  display: flex;
  gap: 16px;
  font-size: 0.9375rem;
}

header nav a {
  color: var(--muted);
  text-decoration: none;
}

header nav a:hover,
header nav a[aria-current="page"] {
  color: var(--accent);
}

h1 {
  font-size: 2rem;
  font-weight: 700;
  margin: 0 0 8px;
}

h2 {
  font-size: 1.25rem;
  font-weight: 600;
  margin: 32px 0 8px;
}

p, ul {
  margin: 0 0 12px;
}

ul { padding-left: 22px; }

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

.effective {
  color: var(--muted);
  font-size: 0.9375rem;
  margin-bottom: 24px;
}

footer {
  margin-top: 64px;
  padding-top: 16px;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.875rem;
  text-align: center;
}