Pseudo elements are visible elements on a web page that aren’t “in the DOM” or created from HTML, but are instead inserted directly from CSS. This allows you to do lots of neat design-y things without cluttering the markup. Pseudo elements are CSS 2, so browser support for them is pretty good!
Links from Video:
- Nicolas Gallagher: interview, multiple backgrounds, icons
- Meet the Pseudo Class Selectors
- Matt Hamm: page curl
- CSS Triangle