body { font-family: -apple-system, Arial, sans-serif; max-width: 720px; margin: 60px auto; padding: 0 20px; color: #222; line-height: 1.6; }
header { margin-bottom: 40px; }
h1 { font-size: 1.6em; }
nav a { margin-right: 16px; color: #555; text-decoration: none; }
nav a:hover { text-decoration: underline; }
footer { margin-top: 60px; color: #888; font-size: 0.85em; }