Horizontal navigation bar moved

I made no changes to the layout or CSS of my site, but all of a sudden my main horizontal navigation bar is all the way to the left now rather than centered with the rest of the site.

I have a child theme set up, so a theme upgrade shouldn’t have caused this, but I don’t know what else might. I have figured out the code which impacts that area and I can change things like the background color, but I can’t get it to really line up right like it should.

Thanks!
Tina

The page I need help with: [log in to see the link]