Having tried to implement some other CSS changes I’m fairly confident that it’s a compatability issue with the Cartpress eCommerce plugin(s) – but you may have some other ideas.
Physically adding a wide banner image as a temporary logo did push the navigation menu below it (understandably) but it’s not accepting the custom CSS to align the nav to the right. Please don’t spend too much time on it at this point – I am in touch with the plugin author/developer. I’ve probably got a box ticked when it shouldn’t be (or vice versa).
It should work in the child theme too. Something is broke in the child theme somewhere. Probably a typo or something.
I know you have removed the menu line from your child styles but I would also point out that the #logo code is not doing anything either. My browser doesn’t apply it. As I said looks like an issue with yoru child theme stylesheet.
The browser is finding the style.css and loads it in the correct place, but ????