nav what just happened

Question

https://code.sololearn.com/WE3nvYeVLnrH/#html
click the hamburger, then snakes, then the navebar do close it
the tabbed page shows onclick of the nav bar but hides with it why?

Answer 1

Now, does anyone know how to make the nav list close on clicking a link?
**edit by calling the original function, this allows it to close on click

Answer 2

Edit: I found the page content it was hovering underneath the top banner.