Question

How would I use @media screen and @-moz-document rules together. Trying to set a rule for only viewing in firefox at a certain width.

Answer 1

Try this

@media screen and (min-width : 500px){

    div { color: green; } // div color green default

    @-moz-document regexp('http:.*'){
        div { color:red; } // red in FF/Gecko
    }
}

DEMO and More Here.