I'm using the
safaribooks to generate ePubs.
The originals look great - the width is dynamic and can be presented on any screen.
One small issue is that this generator doesn't show the cover page in Apple Books, so I'm converting "from ePub to ePub" in calibre. I also generate a version in AZW3 for my Kindle 3 (2010).
Issue with both the output formats is that the max width is now half the size.
I attached a screenshot from original ePub and the generated azw3 (generated epub looks the same).
Also shared picture of how it looks on the iPad and on the Kindle in Landscape (in portrait it actually looks ok).
Issue seems to be that the conversion makes the max-width fixed instead of 100% like before.