Menu broken on mobile view

Steps to reproduce:
1. Open sidebar menu with menu button
2. Swipe content area to the left (as ypu would like to close it)
Content area then overlays the menu, but menu is still visible.

Start by reproducing the sidebar interaction in a mobile view: open the menu, then swipe the content area left to close it. Inspect the theme's mobile menu and content-overlay styling, and consider the issue done when closing the menu no longer leaves the content area overlaid while the menu remains visible.

Written by the indexing model from the issue text.