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

    header {
        background-color: #333;
        color: white;
        padding: 20px;
        text-align: center;
    }

    main {
        padding: 20px;
    }

    .contenedor {
        max-width: 800px;
        margin: 0 auto;
        background-color: white;
        padding: 20px;
        box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    }

    button {
        display: block;
        width: 100%;
        padding: 10px;
        margin-top: 10px;
        background-color: #007BFF;
        color: white;
        border: none;
        cursor: pointer;
    }

    button:hover {
        background-color: #0056b3;
    }

    footer {
        background-color: #333;
        color: white;
        text-align: center;
        padding: 10px;
        position: fixed;
        width: 100%;
        bottom: 0;
    }