Understanding CSS: Thinking inside the box

• The key to understading how CSS works is to imagine that there is an invisible box around every HTML element.
• CSS allows you to create rules that control the way that each individual box is presented.

CSS associates style rules with HTML elements

• CSS works by associating rule with HTML elements. There rules govern how the content of specified elements should be displayed. A CSS rule contains two parts: a selector and a declaration.

CSS properties affect how elements are displayed

• CSS declarations sit inside brackets and each is made up of two parts: a property and a value, separated by a colon. You can specify several properties in one declaration, each separated by a semi-colon.