Restance mobile menu text not visible

I am working on a site using the restance theme. It is all going well apart from when the site is viewed on mobile. The mobile menu is all white and the links are not visible. They are there I just cannot figure out how to change either the mobile menu text colour or the mobile menu background colour. I have not found any specific mobile menu setting yet.

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