This will both remove the blank space as well as add the negative margins? If it only replaces the blank space (like body, div, h1, h2, h3, h4, h5, h6, p {orphans: 1 !important; widows: 1 !important

, then I already add the above in the 'extra CSS window.
I meant can I also add the HTML during conversion, rather than having to open and edit every individual book and add it manually?
EDIT: Actually, just adding both to the 'extra CSS' box appears to actually work, I'll test it on a few and see. I didn't think adding both at the same time would work.
Thanks.