Source: https://divibooster.com/changing-the-website-content-width-on-mobiles/
Divi doesn’t have a setting to change the mobile content width, it’s fixed at 80%. To change it:
@media only screen and (max-width: 980px) {
#top-header > .container,
#main-header > .container,
#et_search_outer > .container,
#main-content > .container,
#main-footer > .container,
#et-footer-nav > .container,
#footer-bottom > .container,
div.et_pb_row,
div.et_pb_row.et_pb_row_fullwidth {
width: 90% !important;
}
}
Code language: CSS (css)