Add the CSS class “flip” to any Divi row settings in the Advanced tab. Add the following CSS code to the Divi theme options area or your child theme style.css file.

[css]
/* swap columns on mobile */
@media only screen and ( max-width: 980px) {
    .flip {
        display: -webkit-flex;
        -webkit-flex-direction: column-reverse;
        display: flex;
        flex-direction: column-reverse !important;
    }
}
[/css]