body { max-width: 720px; margin: 40px auto; padding: 0 20px; font-family: system-ui, sans-serif; line-height: 1.6; color: #222; }
a { color: #1a5fb4; }
header { border-bottom: 1px solid #ddd; margin-bottom: 24px; }
nav a { margin-right: 16px; }
footer { border-top: 1px solid #ddd; margin-top: 32px; color: #666; font-size: 14px; }