Making 3D CSS Flippable Cards

A while back, I wrote an article on 3d interactive CSS buttons. Using a similar technique, I decided to design some 3d interactive (and flippable) CSS user cards. These also work great for lots of different things - for example, a bank card UI, a playing card UI, or just a team's page. The demo can be seen below!

The full code, as always, is available on CodePen.