CSS. Some illegal content.

1. Learn CSS_ Selectors and Visual Rules Cheatsheet _ Codecademy
2. Learn CSS_ The Box Model Cheatsheet _ Codecademy
3. Learn CSS_ Display and Positioning Cheatsheet _ Codecademy
4. Learn CSS_ Colors Cheatsheet _ Codecademy
5. Learn CSS_ Typography Cheatsheet _ Codecademy
6. Learn CSS_ Grid Cheatsheet _ Codecademy

Thanks to Codecademy for informatively designed material.