Cascading consists of supplying several
sources for the style.
In HTML environments there are three
sources: the browser, the user, and the document. Cascading fixes
another weight according to the source of the style. Document
style takes precedence over user style, which takes precedence
over browser style when the specificity number is the same.
There are two more tokens,
!important
and
inherit
. They are used to alter the cascading priority inside
declarations.
A style sheet can also import other sheets
(internal cascading). The syntax is:
@import "[url]" ;
Import statements must precede the first
rule in a style sheet. Priorities of the imported rules are
computed as if the rules replaced the import statements. Here is
an example of import:
@import "common.css" ;