Hola a todos! (Hello, everyone!) In my early days of web design, I had to learn things the hard way: trial and error. There was no Smashing Magazine, Can I Use, CodePen or any of the other amazing tools at our disposal today. Having someone show me the ropes of web design, especially on the CSS front, would have been incredibly helpful. Now that I am far more experienced, I want to share with you in a very friendly, casual, non-dogmatic way a CSS reference guide to pseudo-classes and pseudo-elements.
Source: An Ultimate Guide To CSS Pseudo-Classes And Pseudo-Elements – Smashing Magazine