Theme displays differently on diff devices? backgnd color


(e.g.,) #1

The theme is Magnesium. I have some pages saved out as their own “theme.”
I want a black backdrop in all cases.

In all cases, on an iMac (mine anyway) - it displays black on black.
When viewed on an Apple mobile device, or Android, the backdrop is gray with a black sidebar only.

Huh?