*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg: #ffffff;
  --text: #1a1a1a;
  --muted: #6b7280;
  --border: #e5e7eb;
  --accent: #2563eb;
  --surface: #f9fafb;
  --max-w: 720px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111827;
    --text: #f3f4f6;
    --muted: #9ca3af;
    --border: #374151;
    --accent: #60a5fa;
    --surface: #1f2937;
  }
}

html { font-size: 16px; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

header {
  border-bottom: 1px solid var(--border);
  padding: 1rem 1.5rem;
}

header nav {
  max-width: var(--max-w);
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

header .logo {
  font-weight: 700;
  font-size: 1.125rem;
  color: var(--text);
  text-decoration: none;
}

header nav a {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.875rem;
}
header nav a:hover, header nav a.active {
  color: var(--text);
}

main {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 2.5rem 1.5rem 4rem;
}

h1 {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 0.25rem;
}

.meta {
  color: var(--muted);
  font-size: 0.875rem;
  margin-bottom: 2rem;
}

h2 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-top: 2.5rem;
  margin-bottom: 0.75rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
}

h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-top: 1.5rem;
  margin-bottom: 0.5rem;
}

p, ul, ol {
  margin-bottom: 1rem;
}

ul, ol {
  padding-left: 1.5rem;
}

li {
  margin-bottom: 0.35rem;
}

a {
  color: var(--accent);
  text-decoration: none;
}
a:hover {
  text-decoration: underline;
}

strong {
  font-weight: 600;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 1rem;
  font-size: 0.875rem;
}

th, td {
  text-align: left;
  padding: 0.625rem 0.75rem;
  border: 1px solid var(--border);
}

th {
  background: var(--surface);
  font-weight: 600;
}

hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 1.5rem 0;
}

footer {
  border-top: 1px solid var(--border);
  padding: 1.5rem;
  text-align: center;
  color: var(--muted);
  font-size: 0.8125rem;
}