The style and styleClass attributes allow you to specify Cascading Style Sheets (CSS) styles for the rendered output of your tags. Displaying Error Messages With the h:message and h:messages Tags describes an example of using the style attribute to specify styles directly in the attribute. A component tag can instead refer to a CSS stylesheet class.
The following example shows the use of a dataTable tag that references the style class list-background:
<h:dataTable id="books" ... styleClass="list-background" value="#{bookDBAO.books}" var="book">
The stylesheet that defines this class is stylesheet.css, which will be included in the application. For more information on defining styles, see Cascading Style Sheets Specification at http://www.w3.org/Style/CSS/.