Today I can say that I have used pug. I just followed a few simple steps on some tutorial, but I always want to try those things that seem like I'll never understand.
I also created a 3d square. I think I've tried 3d CSS before, but I don't remember getting very far with it. If possible, I typically try and program things without looking at resources first (just to test my knowledge and memory). There is often a thing or two that I can't remember the exact name of. Or perhaps a step in the process that I forget about.
An article on github reminded me of some important elements that I had forgotten about regarding 3d CSS. You need a container that specifies a perspective, and contains a pixel width and height. And to use
transform-style: preserve-3d; on the main element. Without these elements, anything you try to model will look flat.
It still baffles me how people create complex 3d elements, but this is a good first step and I know that if I keep at it, I'll get there :)