mobile menu doesn't display

Hi all,

Thank you for your help in advance, much appreciated.

I am having two issues;

1) my mobile menu does not display properly. It just shows a blacked out screen when you press the button

2) my mobile site is tiny on the phone..... as in takes up 1/3 of the screen.

Praxisbjj.com is the site

Any thoughts or guesses?

Best,
Larry