Epub3 CSS not implemented on Google Play Books

[leijoninna]

Google Play Books is said to support ePub3, and it sort of does, but the only new feature it seems to support is fixed layout... Well, fair enough for now.

I have tested some of my ePub3 books and most of them works fine as long as they have no audio/video/JS/CSS-animations. But for one book, the reader simply does not implement the CSS. Is still shows one html page per book page but the image sizes, fonts etc are just default values.

The book has no errors in epubcheck 3.0.1, and works fine in iBooks. And I do have a very similar book with the exact same structure (this faulty one was built with the other one as a template), that works as it should in Google Play Books.

Any idea what might be going on? I have checked and compared and checked again but I can see no errors in the html files, the css file, nor the content file. I can attach examples but I am pretty sure this does not have to do with the code itself.