If you want the outline to be always visible, I think that using a separate background for the outline, to distinguish it from the main content, would be a bett

If you want the outline to be always visible, I think that using a separate background for the outline, to distinguish it from the main content, would be a better solution then having a new background on which both the outline and the main content are elements. I recently saw a website on HN which I felt had a well designed outline like this - visible but not distracting[1]. My reader app has few users, and I don't track how they use it. I guess even with that model one could make it discoverable with some kind of tutorial, but I always find tutorials kind of annoying. The first time you use an app, when the tutorial is usually shown, you don't want to do a tutorial, you don't care for any advanced features. Maybe the VS Code model - one sidebar that is always visible with different vertical tabs to choose what to show (notes, table of content ...) might work better. Edit: Just implemented that in 1paragraph[2]. (You'll have add a book to see it, since the default "book" doesn't have an index.) [1]: https://writequit.org/eos/eos.html https://writequit.org/eos/eos.html [2]: https://1paragraph.app/ https://1paragraph.app/