>>75806
>how to make the game cds not fall over when opening the place they're in

i played 2000 hours of factorio, i was born to answer this.

i just found out how this is called what you are looking for: lever style bookend.

in it's most basic form it is just a small piece of thin metal with one right angle bend into. you could easily bend one yourself if you are lucky and find a piece of metal that has an acceptable dimensions.

you place one side underneath the cds, gravity is pulling them down thus applying force to hold the metal piece in place. then the other side keeps the discs from tipping over, using their own weight against them.

similar principle to the belt loops holding up the belt in place while the belt is holding the pants in place.

the one in the picture is fancy, i have simple ones from thin metal that was painted white.