How to make 3d flip effect?

Question

css

Hello
There is such a block flip: https://codepen.io/lightalex/pen/NvJjZx
It became interesting whether it is possible to make this card "thick"?
How to add Z volume to a block?
For now, it's just a matter of spawning divs and spreading them along the Z axis to get a fake volume.
But I don't like this idea
. Maybe there are some magic functions that will allow you to drag the block along Z?
PS Please note that the card has rounded edges, which does not allow you to add three divs that will create a 3D shape

Answer 1

Demo (codepen)

Answer 2

https://codepen.io/anon/pen/GveQKd