2x3 grid for images on mobile

Site URL: http://www.grayn.io/superusers

Hi! 
I'm looking to arrange 6 illustrations in a 2rowsx3images grid on mobile. Now it is showing as just 1 image per row.

Add to Design > Custom CSS

@media screen and (max-width:767px) {
div#block-yui_3_17_2_1_1643013318310_21843+.row>.span-2 {
    width: 33.3333% !important;
    float: left !important;
}

div#block-yui_3_17_2_1_1643013318310_21843+.row>.span-6 .span-2 {
    width: 33.3333% !important;
    float: left !important;
}

div#block-yui_3_17_2_1_1643013318310_21843+.row>.span-6 .span-2 * {
    font-size: 12px;
}
}