View source for Cascade (CSS)

In [[Cascading Style Sheets]], the '''cascade''' refers to a set of principles which determine how style rules interact with [[HTML]].

== Basic principles ==

The [[Cascade (CSS)]] refers to the way that CSS deals with multiple style rules, when the rules apply to a single specific [[HTML element]].

=== When rules do not conflict, they combine ===

Both rules apply, when they do not conflict with each other.

=== When rules conflict, highest cascade weight wins ===

[[Cascade weight (CSS)]] is a measure of how important a rule is, among all rules which affect a give web page.

When two or more rules conflict, the rule with the highest [[Cascade weight (CSS)]] applies.  The other rules are ignored.

It is not necessary to calculate, or know, the numeric value of the weight (although you can look it up using [[Inspect Element]]), if you are curious).

More important, you should know the general principles of the cascade.  You will be able to judge the weight intuitively, with practice.

See also:

* http://code.karljones.com/docs/css/CSS-part-02.pdf