Fixing .site-overlay not displaying

Oddly, .site-overlay was not displaying when the menu was toggled, even with.
{ position: abolsute; left: 0; right: 0; top: 0; bottom: 0 }
So with a mobile or with my desktop browser I was able to scroll left-to-right in #container.

I fixed it adding a simple {min-height: 100%}