CSS rules are made up of selectors and declarations. A selector is used to target an HTML element, while declarations contain rule properties and values that are applied to the targeted element.

Understanding how browsers parse CSS and render websites is an important first step towards writing more efficient code. In this first piece on efficient CSS, we look at selectors, how the browser ...

Ryan Boudreaux covers the basics about CSS specificity hierarchy in an effort to make this tricky concept easier to understand.