float property is one of those CSS rules which are somehow difficult to understand. Before a couple of days I had a problem with floating divs. I solved it and decided to write an article about the solution. The article also covers some basics about floating.
By definition :before and :after are CSS pseudo elements. You can use them to insert something before or after the content of an element. There are some great articles giving the basics, but I wanted to write down a blog post for the real use cases. Or, at least, to show what I'm using them for.