Change selection highlight color in Casper theme

Themes
1

Hi there,

I’m using the Casper theme (v 5.11.1) with automatic switching between light and dark modes for accessibility.

The problem I’m encountering is that when selecting text in posts, the highlighting color is the same for both light and dark mode, which means that the dark mode selected text cannot be read because it doesn’t contrast well with the highlight color. (see images).

Screenshots
Screenshots1492×1112 281 KB

I tried changing ::selection background color in the global.css file, but that broke the whole theme.

Is there any way to change the selection color on the text body for Casper? alternatively, how do I get it to have a different selection color in dark and light modes for better visibility?

Thanks!