CSS - Inheriting layered background images

That is, in any case, not the way CSS inheritance works. inherit implies that an element should take on the attributes of it's parent element, not previous declarations affecting the same element.

What you want has been proposed as a way to make CSS more object-oriented, but the closest you will get is with a pre-processor like SASS.

For now you actually just have to re-state the first image along with the second.

I don't think this is possible, I think you'd have to redefine the whole rule every time.

For example, you could just add a "wrapper" around every item that has the initial background, with the actual item having a transparent background. Then add the background on the item itself when it's selected.