Thank you @tuanphan, that worked perfectly, the mobile menu no longer appears on the site.
I went to Settings > Advanced > Code Injection and added it to the <HEADER> section.
One last question, how do I make the just darken slighlty, say a 90% transparency so that there is some definition behind the logo and the content. Is there a place to do that? On the 7.0 interface I believe there was a control for that but I don't see it here.
Thank you!