Additional Library - general-footer-fullcontent
Additional Library - general-footer-fullcontent extends the Contact information section to the full width of the footer's content area and has the navigation appear below it.
With this additional library applied. The Contact information section of the footer will fill up the footer's content area. The navigation will appear after it as a second row.
Background colours for the footer sections can be set to the same colour in the site's theme. So that they appear as one section.
You can use the Grid classes to separate content in the footer into columns.