body { font-family: sans-serif; margin: 0; padding: 0; }
header { background: #000; color: #0f0; padding: 1em; text-align: center; }
nav a { color: #0f0; margin: 0 1em; text-decoration: none; }
section { padding: 2em; }
footer { background: #222; color: #fff; padding: 1em; text-align: center; }