Currently in Zotero 7, we have to select a font to be used for epub books in settings, but changing font sometimes looses the formatting, currently I'm reading a book, which uses I don't know which font, to number some lines, but if custom font is used, these becomes symbols and hard to understand which line that is. but in other reader, if I select book font, then everything is rendered perfectly, so we definitively need an option to use the font that is included in the book.