@media only screen and (max-width: 350px) {
    body {
        font-size: 8px;
    }
}
@media only screen and (min-width: 350px) {
    body {
        font-size: 9px;
    }
}
@media only screen and (min-width: 500px) {
    body {
        font-size: 11px;
    }
}
@media only screen and (min-width: 650px) {
    body {
        font-size: 13px;
    }
}

pre { 
    margin: 0; 
}

h1 { 
    text-align: center; 
}

.centered {
    margin: 0 auto 0 auto; 
    padding-top: 25%;
    width: 90%;
    max-width: 500px;
}