Use this handy, simplified guide to quickly learn HTML and CSS -- a foundation of modern web development.

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.

Using a background replaces the boring white background in Excel. Getty Cascading Style Sheets (CSS) level 3, also known as CSS3, introduces multiple background images support.