https://www.w3schools.com/css/default.asp

https://html5book.ru/css-css3
https://web.dev/learn/css/

2024
Natalia Davydova - Drawing on CSS
    https://www.youtube.com/watch?v=yfy2vjzde-A
        https://codepen.io/nat-davydova/pen/YzbWqgG/400d03c1030bc6eaf78001d6b05e9c8a
    https://www.youtube.com/watch?v=-VH72Q88iEg
2018
Academind - Getting Started with CSS
    https://www.youtube.com/watch?v=wNX7lWzchow