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.

Tony Patton focuses on CSS fundamentals and explains how multiple rules for the same element are handled. Multiple rules ensure that there will be no surprises for either you or the user community.

If you've made the leap to a CSS preprocessor like SASS or LESS, fear not, Idiomatic CSS has you covered as well.Preprocessor syntax varies and Idiomatic CSS offers examples in SCSS, but the more ...