Using M3 screws, you can easily assemble shelves from Alu-profiles (10x10 - Hornbach, OBI), which you can design yourself to your dimensions.
You need a couple of screws and nuts (M3), a drill with a drill and a saw :) I will add photos from the implementation later - I am printing it now....
So, wait for the photos soon
The author marked this model as their own original creation.