Learning PHP, MySQL, JavaScript, and CSS, 2nd Edition

Style Types

There are a number of different style types, ranging from the default styles set up by your browser (and any user styles you may have applied in your browser to override its defaults), through inline or embedded styles, to external style sheets. The styles defined have a hierarchy of precedence, from low to high.

Default Styles

The styling with the lowest level of precedence is the default styling applied by a web browser. These styles are created as a fallback for when a web page doesn’t have any styles defined; they are intended to be a generic set of styles that will display reasonably well in most instances.

Pre-CSS these were the only styles applied to a document, and only a handful of them could be changed by a web page (such as font face, color, and size, plus a few element sizing arguments).

User Styles

User-defined styles have the next-highest precedence; they are supported by most modern browsers but are implemented differently by each. If you would like to learn how to create your own default styles for browsing, use a search engine to enter your browser name followed by “user styles” (for example, “Firefox user styles” or “IE user styles”). Figure 18-2 shows a user style sheet being applied to Microsoft Internet Explorer.

Figure 18-2. Applying a user style to Internet Explorer

If a user style is assigned that has already been defined as a browser ...