Toggle Divi Theme Submenu on Mobile [CSS]

#main-header .et_mobile_menu li ul.sub-menu.hide {
    display: none!important;
}

#main-header .et_mobile_menu li ul.sub-menu.visible {
    display: block!important;
}

.et_mobile_menu .menu-item-has-children > a:after {
        content: '';
        width: 0;
        height: 0;
        border-left: 7px solid transparent;
        border-right: 7px solid transparent;
        border-top: 7px solid #ffffff;
    position: absolute;
        right: 25px;
}

.et_mobile_menu .menu-item-has-children > a:hover:after {
    border-top: 7px solid #cc0000;
}