body {
    background-color: #ddd;
}

form {
    max-width: 25em;
    margin: auto;
}

.bloques {
    display: block;
    margin-top: 1em;
}

.formato {
    background-color: burlywood;
    font-size: 1.2em;
    padding: .5em;
    border-radius: .5em;
    border: 1px solid #999;
    font-family: Arial, Helvetica, sans-serif;
}