PurgeCSS with epub file

[Iaabel]

Hello,

I often do epub files which includes CSS with a large amount of unnecessary rules and was wondering how to solve this problem... I learned about PurgeCSS but is it really possible to use it on an epub file ? (I'm not really a programmer or anything, but I rather spend some time learning how to use this tool than removing tons of rules by hand to be honest). I've read documentation but this case do not seem to be considered.

(I'm french, hope my english is ok)

Thanks a lot for reading me !