Safari ignoring css max-width media queries below a certain point

Turns out I was missing a squiggly brace, so I had code like the following:

@media screen and (max-width: 767px){
    /* lots of css */
    .some_selector { padding: 20px; /*<---- missing squiggly brace*/
    /* more css */
}
@media screen and (max-width: 640px){
    /* lots more css */
}

Inserting the missing brace caused Safari to begin working. Other browsers didn't choke on the error which is partially why it was so difficult to track down.

Thanks for the help everyone, I feel pretty silly now.