body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
}

header {
    background-color: #4CAF50;
    color: white;
    padding: 1em;
    text-align: center;
}

main {
    padding: 2em;
}

a {
    display: inline-block;
    margin-top: 1em;
    color: #4CAF50;
    text-decoration: none;
}