Firstly I would like to congratulate the team for such a great software.

Secondly I would like to offer a suggestion:

**Offer a "inverted colour" / "night-mode" reading option (most pdf readers offer this)**.

Rationale:

As a person who likes to read on the computer, precisely because I can highlight, annotate and export my notes so easily, I tend to read pdfs (and ebooks) "inverting" the colors (some pdf readers/viewers call this "night mode); the reason for this is because it causes much less eye-strain, than the common white background of a normal pdf.

Perhaps it is not something everybody likes, but at least it is quite common among people (researchers) I know.