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 ... why you should use it.

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 ...

You'll be taught how to use HTML and CSS, and by the end of the course, you'll be able to complete a project in both languages. Once you've completed the first course, you can expand your skillset ...