body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
}
header {
    background: #444;
    color: #fff;
    padding: 1em;
}
header nav a {
    color: #fff;
    margin: 0 1em;
    text-decoration: none;
}
main {
    padding: 2em;
}
footer {
    background: #eee;
    text-align: center;
    padding: 1em;
    margin-top: 2em;
}