Targeted iBooks mode css

[scruffs]

Please forgive if this is not the correct forum.

I am trying to target the background mode on Apple Books in CSS.

I can get sepia working with:

:root[__ibooks_internal_theme*="Sepia"]
div.thing {
background-color : #ffff00;
}

but I cannot get Night or Gray working with:

:root[__ibooks_internal_theme*="Night"]
div.thing {
background-color : #00ffff;
}


Info on the web seems to indicate that it should work.

:-/

[kyteflyer]

Do you have to define the background colours? I thought those were part of the app itself, like the fonts. You’re only allowed access to a subset of the available fonts on the device.

[scruffs]

So far as I can see it is literally impossible to create a single image with opacity that meets minimum accessibility requirements across all four theme modes.