body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
}
header {
    background: #333;
    color: white;
    padding: 1em;
    text-align: center;
}
nav a {
    margin: 0 10px;
    color: white;
    text-decoration: none;
}
main {
    padding: 2em;
}
footer {
    text-align: center;
    padding: 1em;
    background: #f0f0f0;
}
.button {
    display: inline-block;
    margin: 1em 1em 0 0;
    padding: 10px 15px;
    background: #0077cc;
    color: white;
    text-decoration: none;
    border-radius: 5px;
}