Transparent Page-Menu / Youtube integration

Hi,
the theme is really beautiful but I have two severe issues with it:
a.) when having sub pages in the page navigation then the menu shows them with white text on a transparent background (so you don’t see them if the backgroundcolor of the site is white). You can see my example on https://www.abhati.ch/current-bugs

b.) The shortcode for youtube doesn’t work f.e
[youtube=https://www.youtube.com/watch?v=FwAj3qTPt4E]
is this a bug as well?

Any help is appreciated, Best Regards Palo