: Ensure the EPUB CSS is compatible with system-level dark themes.

: Excellent for managing large Russian-language libraries. To help you further, could you clarify your goal? Are you a developer looking to build a download feature?

If you are looking for software to these files, here are the top choices:

: Ensure files include correct author, title, and cover art.

: Option to "Send to Kindle" or sync directly to Google Drive/Dropbox.

: Users generally prefer files without Digital Rights Management for easier transfer.

: Quick toggles to find books in Russian, English, or other languages. 📚 Technical Implementation Preferred EPUB Specifications EPUB 3.0 : Support for reflowable text and multimedia.