Highlighting text of source pdf during flashcard review mode and percentage of source covered

Hi, please add a feature that higlights the exact words/lines on the source pdf when we check it during flashcard review.
Also, how much percentage and what lines of the source pdf are already covered in flaschard creation and ability to generate more flashcards from the lines not covered by flaschard creation before. For how it works, please check the flashka app. They have done it well but I am liking the AI in your app along with other features.

The above featuers ensure that the complete pdf is covered by flashcards and also the context is improved during review. Thanks.