Usability - left/right arrow keys navigating topics is not great

Problem:
Just started working through the examples. Switching back and forth through browser tabs of documentation and back to the 'book' means I'm not necessarily remembering or aware of the in-browser keyboard focus it isn't indicated well. I go to move the cursor around in the code editor box only to find out that wasn't where keyboard focus was by seeing topics fly by. This also means all my edits are gone.

Fix?:
Personally I wouldn't expect to navigate the book as tho it were a slideshow due to the interactive content. This leads to my first suggestion which is to just don't have those key bindings. On the other hand I'm typing this into github which has a well indicated keyboard focus dialog surround in an obvious color. This contrasts strongly to the tiny input cursor grey-out/highlight depending on focus within the 'book'

I'm no UX guy, so expect it's up to 'you' and/or some discussion to decide whether and how to address this.

Thanks!

No file, test, or entry point is named in the issue. First clarify with maintainers whether arrow-key navigation should be removed or improved, then identify the relevant book and editor UI code; done means the chosen behavior is clear to users and editing is not lost when focus is unclear.