The CSS You Need for JavaScript

Read a CSS rule's selector, properties and values, pick elements by tag name, class, id or what they're inside, and see how a class added or removed by JavaScript changes the way an element looks.

Updated

Cheat sheet: The CSS You Need for JavaScript
Category
JavaScript
Level
Novice
Tags
Class selector, CSS, CSS rule, Descendant combinator, ID selector, JavaScript, Property (css), Selector (css)