The buzzword CSS4 came out of nowhere, just as Andrzej Mazur was getting used to the fact that CSS3 is here and will stick around for some time. Browser vendors are working hard to implement the latest features, and front-end developers are creating more and more tools to be able to work with the style sheets more effectively. But now, on hearing about CSS4, you might ask, Hey, what about CSS3? Is it over already?
Selectors are the first document to reach the fourth level of the specification, and it’s still a draft, a work in progress. Each document is on its own when it comes to the specification number; the documents are developed independently of each other. The specification explains selectors as patterns that match against elements in a tree. Most of the selectors from the Level 4 specification are pseudo-classes. Selectors have been with around since the beginning of CSS, but now they are at the fourth level and have gotten a lot of cool new additions. Let’s jump into the action and see what’s interesting. Andrzej Mazur will not describe the entire document — only the new additions in Level 4.