styles, including !important author styles. Both author and reader styles override the user agent's default styles. 3. Sort by specificity all declarations applying to a given el- ement. Those elements with a higher specificity have more weight than those with lower specificity. 4. Sort by order all declarations applying to a given element. The later a declaration appears in a style sheet or a docu- ment, the more weight it is given. Declarations that appear in an imported style sheet are considered to come before all declarations within the style sheet that imports them, and have a lower weight than those in the importing style sheet. Any presentational hints that come from non-CSS sources (e.g., the preference dialog within a browser) are given the same weight as the user agent's default styles (see step 2 above). Element Classification Broadly speaking, CSS groups elements into two types: non- replaced and replaced. Although the types may seem rather ab- stract, there actually are some profound differences in how the two types of elements are presented. These differences are explored in detail in Chapter 7 of CSS: The Definitive Guide, third edition (O'Reilly). Nonreplaced Elements The majority of HTML and XHTML elements are nonreplaced elements, which means their content is presented by the user agent inside a box generated by the element itself. For example, <span>hi there</span> is a nonreplaced element, and the text hi there will be displayed by the user agent. Paragraphs, head- ings, table cells, lists, and almost everything else in HTML and XHTML are nonreplaced elements. Element Classification | 9