https://nandgame.com/ https://nandgame.com/ has a cmos level towards the end. It doesn’t explain the transistor-level physics but does let you play with things.

https://nandgame.com/ https://nandgame.com/ has a cmos level towards the end. It doesn’t explain the transistor-level physics but does let you play with things. The art of electronics book might be a good place to start if you want to learn the physical/electrical layer.