https://wiki.selfhtml.org/wiki/CSS
https://wiki.selfhtml.org/wiki/CSS/Tutorials/Einstieg
https://www.mediaevent.de/css/eigenschaften.html
https://www.w3.org/Style/CSS/learning
https://wiki.selfhtml.org/wiki/CSS/fertige_Layouts
CSS Tricks: Artikel, Almanach uvm.
A visual guide to CSS selectors
CSS Lernspiele:
Fonts einbinden:
https://www.mediaevent.de/css/font-face.html
https://css-tricks.com/snippets/css/using-font-face-in-css/
Icons:
https://www.sandstein.de/internetagentur/icon-fonts-oder-svg-grafiken.php