This question leads to one of the most important ideas behind CSS: The selector, so named because it’s the way we “select” the HTML we want to style.

CSS selectors are patterns used to select Web site elements to be styled in various ways, including some 500 properties for color, fonts and so on. While basically universally required in Web ...

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.