jsFiddle is the perfect solution; it provides a custom environment (based on user selections) to test (or fiddle with) your JavaScript, HTML, and CSS code right inside your browser. A quick tour ...

Cascading Style Sheets (CSS) first dropped in 1996 ... us is a way to negatively define non-active portions of the user interface, whereas before we had to positively define the active parts.

Whether you're building a Web or desktop application, here's a round-up of tools for building the interface with plain old HTML. Being able to work comfortably on Web-related code elements -- HTML, ...

This definition explains the meaning of CSS (cascading style sheets) and how using them with HTML pages is a user interface (UI) development best practice that complies with the separation of concerns ...