https://www.youtube.com/watch?v=G3e-cpL7ofc&list=WL&index=1&t=148s
https://supersimpledev.github.io/references/html-css-reference.pdf
https://github.com/SuperSimpleDev/html-css-course-2022/tree/main/1-exercise-solutions
- box model
- display: block/inline-block/inline
- div & nested layout
- grid
- flexbox & nested flexbox
- position: fixed/relative/absolute
- media query
- inheritance