In addition to creating templates that are displayed conditionally, the Drupal system also enables you to apply CSS selectively. Drupal creates unique identifiers for various elements of the system and you can use those identifiers to create specific CSS selectors. As a result, you can provide styling that responds to the presence (or absence) of specific conditions on any given page.
One of the most useful dynamic styling tools is
. This variable is intended specifically as an aid to dynamic CSS styling. It allows for the easy creation of CSS selectors that are responsive to either the layout of the page or to the status of the person viewing the page. This technique ...