Readability

What are the potential problems posed by style sheets?

Style sheets can enable users to define specific viewing preferences to accommodate their disability. For instance, users with low vision may create their own style sheet so that, regardless of what web pages they visit, all text is displayed in an extra large font with white characters on ablack background. If designers set up their pages to override user-defined style sheets, people with disabilities may not be able to use those pages. For good access, therefore, it is critical that designers ensure that their web pages do not interfere with user-defined style sheets.

In general, the "safest" and most useful form of style sheets are "external" style sheets, in which the style rules are set up in a separate file. An example of an external style sheet is: