body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #111;
    color: #fff;
}
header {
    background-color: #222;
    padding: 2rem;
    text-align: center;
}
main {
    padding: 2rem;
}
section {
    margin-bottom: 2rem;
}
footer {
    text-align: center;
    padding: 1rem;
    background-color: #000;
    font-size: 0.9rem;
    color: #aaa;
}