/* Guesswork from inspecting a random page. */
/* writeup - class for original posts (?) */
#writeup {
    font-size: 1.5em;
    /* or 1.5rem, or 150% */
}
/* reply-body - class for responses (?) */
#reply-body {
    font-size: 1.25em;
    /* or 1.25rem, or 125% */
}