body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f4f4f4;
}

header {
    background: #333;
    color: #fff;
    padding: 1rem;
    text-align: center;
}

header nav a {
    color: #fff;
    margin: 0 1rem;
    text-decoration: none;
}

main {
    padding: 2rem;
    text-align: center;
}