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

header {
    background-color: #333;
    color: #fff;
    padding: 1em;
    text-align: center;
}

main {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 2em;
}

button {
    background-color: #333;
    color: #fff;
    border: none;
    padding: 1em 2em;
    cursor: pointer;
}

footer {
    background-color: #333;
    color: #fff;
    padding: 1em;
    text-align: center;
    clear: both;
}