Full width navigation

Instead of the menu beginning about halfway across the page, I’d like it to extend the entire width. Is there a best way to accomplish this so it doesn’t revert back when the theme is updated? I’m using a child theme, so I’m not sure why it reverted. The site is at http://restorationbiblechurch.org/


You just need to add this in your child theme’s style.css:

.main-navigation {
     width: 100%;

You probably had the changes in your parent theme, that’s why it reverted.