Here is a handy mobile optimised navigation menu that sites at the bottom of the screen, the hamburger menu is conveniently placed in the center so it’s easily accessible by both left and right-handed users. It was designed by Stas Melnikov.
If you are having trouble with the pen, try the archived copy on GitHub
Bottom Edge Mobile Menu Snippet
See the Pen Mobile Menu Animation by Stas Melnikov (@melnik909) on CodePen.0