A CSS selector can contain more than one simple selector. Between the simple selectors, we can include a combinator. There are four different combinators in CSS3: What are Pseudo-classes? A pseudo-class is used to define a special state of an element. For example, it can be used to: Style an element when a user mouses over it 5.8 Attribute selectors. CSS 2.1 allows authors to specify rules that match elements which have certain attributes defined in the source document. Sketch 3 has design templates included, and many of those have icons in them. This is an easy way to get started, both with icons and with your user interface design. Yet another useful thing that pseudo elements can do for us: allow us to create full browser width header bars without using internal non-semantic wrappers. I Cant believe that only now i came across that perfect post. After working with css for a very long time, it’s good to get rid of old habits and learn something new :) Learn CSS, HTML and Responsive Web Design with Max Design’s Russ Weakley Pattern Meaning Described in section First defined in CSS level * any element Universal selector: 2 E an element of type E.