[JSWolf]

Originally Posted by DNSB

I was under the impression that ADE2 disregarding the entire style sheet after an error was triggered by a structural error in the stylesheet not by an correctly structured unknown item. A missing { or } for instance.

RMSDK (ADE3 version) used by Kobo will ignore the entire stylesheet with what is thought to be an error.

Here is code that ADE 2.0.1 thinks is an error from a StandardEbooks CSS. It's code that will not work in most cases anyway. So there's no need for it.

@media all and (prefers-color-scheme: dark) {
  img.epub-type-se-image-color-depth-black-on-transparent {
    filter: invert(100%);
  }
  img.epub-type-se-image-color-depth-black-on-transparent.epub-type-se-image-style-realistic {
    background: currentColor;
    filter: none;
  }
}
@media all and (prefers-color-scheme) {
  img.epub-type-se-image-color-depth-black-on-transparent:not(.epub-type-se-image-style-realistic) {
    background: transparent !important;
  }
}