body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background: #f4f4f4;
}
header {
    background: #333;
    color: white;
    padding: 20px;
    text-align: center;
}
section {
    max-width: 800px;
    margin: 20px auto;
    padding: 20px;
    background: white;
    border-radius: 8px;
}
footer {
    text-align: center;
    padding: 10px;
    color: #666;
}