body { font-family: Arial, sans-serif; margin: 0; padding: 0; }
header { background: #222; color: #fff; padding: 1em 0; }
nav ul { list-style: none; display: flex; justify-content: center; gap: 20px; margin: 0; padding: 0; }
nav ul li a { color: #fff; text-decoration: none; }
footer { background: #222; color: #fff; text-align: center; padding: 1em 0; margin-top: 20px; }
main { padding: 20px; max-width: 900px; margin: auto; }