Lowers the fixed backing layer to z-index 1 and adds z-10 to
the main content area. When at the top of the page, the backing
provides the 85% opacity behind the header. When scrolled, the
content area (z-10) occludes the backing (z-1), so only one
layer of 85% is ever behind the header — matching the tab bar.
Lemon
1fd3be1ca5