The Divi theme includes a footer containing, among other things, a bottom bar which displays copyright / credit links, and social icons. The default width for the content in this bar is 80% of the screen width, with a maximum width of 1080px. If you'd like to change the footer bottom bar width, here's how.

Changing the Website Content Width

Divi includes an option to adjust the content width for the entire site, which you can find at:

Divi > Theme Customizer > General Settings > Layout Settings > Website Content Width

The footer bottom bar's max width is derived from this setting. This means that increasing the website content width would allow the footer bottom bar to be wider on large displays.

Note that this setting also affects the width of content elsewhere on the site, such as the header and body.

Changing the Footer Bottom Bar Width with CSS

Using CSS, it's possible to precisely control the footer bottom bar width. For example the following CSS will set the footer bottom bar width and max width to the same value (90vw in this case) to ensure the footer bottom bar always takes this setting, regardless of the browser width:

Related Post: Adding CSS to the Divi Theme