ID (#) selector
Matches the id attribute of the specified element.
String that specifies the value of the "id" attribute.
- CSS 2.1, Section 1.5
The id attribute allows authors to uniquely identify an element instance in the document tree. ID selectors match an element instance based on its identifier. The id attribute value must immediately follow the "pound" (#) notation.
In the event that a style declaration conflicts with another declaration, the rule with a higher level of specificity is used. (See Understanding CSS Selectors.) If a Class Selector and ID Selector are in conflict, the id is chosen.
The following style rule applies to the element with id="navigation" and its descendants.