If I were creating a mobile-first site, I would want to adjust all widths to fit within the frame. Furthermore, I would remove the background for clarity. With a small screen, this padded space is unnecessary and makes the site difficult to see. Furthermore, I would adjust the navigation from a horizontal area to a vertical one. All of these changes are essential so that when the user opens the site on a mobile device, they would never need to scroll horizontally to view the entirety of the layout and content.!