body {
    margin: 0;
    padding: 0;
    font-family: sans-serif;
    background: #f4f4f4;
    color: #222;
}

header {
    background: #222;
    color: #fff;
    padding: 1rem;
    text-align: center;
}

main {
    padding: 2rem;
}

button {
    padding: 0.5rem 1rem;
    font-size: 1rem;
    border: none;
    background: #007bff;
    color: #fff;
    cursor: pointer;
    border-radius: 3px;
}

button:hover {
    background: #0056b3;
}