Div height:0px does not work?

Question

Setting a div height to 0px does not seem to work.

The div expands to show it

Answer 1

#yiv1734505183 .yiv1734505183portrait{
    display:none;
    font-size:0;
    max-height:0;
    line-height:0;
    padding:0;
    overflow:hidden;
}

@media (min-width:481px){
    #yiv1734505183 .yiv1734505183mobile-hide{
        display:block;
        overflow:visible;
        width:auto !important;
        max-height:inherit !important;
        min-height:auto !important;
    }
}
@media (min-width:481px){
    #yiv1734505183 .yiv1734505183portrait{
        display:none;
        font-size:0;
        line-height:0;
        min-height:0;
        overflow