|
Typically, EPUB reader apps, including iBooks or Apple Books, render HTML/CSS/Javascript by using a web browser component bundled with the operating system such as macOS or iOS. Thus, the difference you observed may be due to the difference in the system web browser component on macOS and iOS. It may also be due to different version numbers.
One way to explore the issue is to view individual HTML files with Safari browser running on macOS and iOS respectively. If both sets of results are the same, then the bug is probably with the app. Otherwise, it's likely to be the OS.
Moreover, try it with a different ebook reader app to see what results you'll get.
|