body {
    font-family: Arial, sans-serif;
    background-color: #ffffff;
    color: #000000;
    margin: 0;
}

header,
footer {
    background-color: #003366;
    color: white;
    padding: 15px;
    text-align: center;
}

/* Menú de navegación */
nav ul {
    list-style: none;
    display: flex;
    justify-content: center;
    padding: 0;
    background-color: #eeeeee;
}

nav ul li {
    margin: 0 15px;
}

nav ul li a {
    text-decoration: none;
    color: #003366;
    font-weight: bold;
}

.contenedor {
    width: 80%;
    margin: 0 auto;
    text-align: center;
}

button {
    display: block;
    max-width: 250px;
    padding: 10px 20px;
    margin: 20px auto;
    font-size: 16px;
    cursor: pointer;
}

ul {
    list-style-position: inside;
    padding: 0;
    display: inline-block;
    text-align: left;
}