body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  max-width: 720px;
  margin: 0 auto;
  padding: 24px 20px 64px;
  line-height: 1.6;
  color: #1a1a1a;
  background: #fafafa;
}
h1 { font-size: 1.6rem; }
h2 { font-size: 1.2rem; margin-top: 2rem; }
a { color: #2952e3; }
nav { margin-bottom: 32px; }
nav a { margin-right: 16px; }
.updated { color: #666; font-size: 0.9rem; }