Instead of using the Calibre GUI, which is nightmare fuel, I recommend Calibre's command line conversion tool `ebook-convert`: https://manual.calibre-ebook.com/

Instead of using the Calibre GUI, which is nightmare fuel, I recommend Calibre's command line conversion tool `ebook-convert`: https://manual.calibre-ebook.com/generated/en/ebook-convert.html https://manual.calibre-ebook.com/generated/en/ebook-convert.... It's kind of like pandoc, except pandoc only supports epubs.