[stumped]

thanks guys, this is a out-of-curiosity study of an existing book's code, it's not something I created or something I plan to keep. Just wanting to understand the rendering mechanics here.
i did read some mostly old threads on shrinking via calibre conversions, but I really wanted to know if the rendering can be made more app friendly just by simple regex/ css changes.


i had not encountered vh before & guessed it means vertical height- google tells me it actually means viewport height - so what is 98vh asking the rendering engine to do, exactly

to answer another question: in the source epub3 format there is no css class for img.

if i have calibre do an epub to epub conversion - thus making it epub 2, the post conversion version actually renders better in ade 2.0.1, i.e. the images then do scale to fit PC window, but is still unviewable in moon+ reader.
calibre leaves the div css unchanged but adds this CSS for img
display: inline;
height: auto;
max-height: 100%;
max-width: 100%;
page-break-inside: avoid;
width: auto

the book is a huge, over 100Mb file, because of the over-the-top images used ( it's only 50 pages! ) so I am not wanting to share it even privately for study, just wanting to understand how it could have been done better / made much smaller to suit a typical tablet or eink device. Most images are 24 bit colour, some are 32 bit - that., plus the dimensions seems overkill - as if someone said lets just put the master print images into the ebook , unscaled.

& i thought that most professionals used svg tags nowadays to pair with .png, not basic img ?