Advise on bookshelf design


I am new here. I was wondering if I can get some feedback on a design I am doing. I am creating a bookshelf and I would like the end to be somewhat circular.

The part that I am having the problem with is that when I place a book to the far end of the shelf it will face a circular edge and would be unstable and might fall. This area where the straight edge of the book and the curved edge of the book is where I need help with.

Here are some ideas to solve the problem: Plate design is a plate with some space as follows:
Here is another design with the plate fully covered:
Finally here is a design where the geometry is somewhat adopted to make the design:
What do you guys think? Can you give me some feedback? I haven’t taken any industrial design courses. Is this kind of thing taught in college? Is this kind of form problems taught?