Originally Posted by kovidgoyal
IIRC ADE doesn't support all the CSS 2 .1 background properties, so you may not have much luck with this. Though maybe the newer ones do.
I just tested it. It doesn't quite work right in the calibre ebook-viewer or Adobe DE. But it works well enough that I think the problem is caused by my limited knowledge of css+html.
Would any of our more experienced members like to take a shot?