div.paragraph {
    margin: auto;
    padding-top: 1em;
    max-width: 50em;
    font-family: arial, sans-serif;
    font-size: 125%;
}

@media (max-width: 1000px) {
    div.paragraph {
        max-width: 35em;
    }
}

@media (max-width: 600px) {
    div.paragraph {
        max-width: 15em;
    }
}