CSS cascading and inheritance

The CSS cascading and inheritance module defines the rules for assigning values to properties by way of cascading and inheritance. This module specifies the rules for finding the specified value for all properties on all elements.

One of the fundamental design principles of CSS is cascading of rules. It allows several style sheets to influence the presentation of a document. CSS property-value declarations define how a document is rendered. Multiple declarations may set different values for the same element and property combination, but only one value can be applied to any CSS property. The CSS cascade module defines how these conflicts are resolved.

The opposite also occurs. Sometimes there are no declarations defining the value of a property. The CSS cascade module defines how these missing values should be set via inheritance or from the property's initial value.

Note: The rules for finding the specified values in the page context and its margin boxes are described in the CSS page module.

Reference

Properties

At-rules

Keywords

Interfaces

Glossary and definitions

Guides

Introducing the CSS Cascade

Guide to the cascade algorithm that defines how user agents combine property values originating from different sources.

CSS inheritance

A guide to CSS inheritance.

CSS property value processing

Value processing in CSS, including the different stages of CSS property values, from specifying to rendered values.

Learn: Handling conflicts

The cascade, specificity, and inheritance, which together control how CSS is applied to HTML and how conflicts are resolved.

Learn: Cascade layers

Introduction to cascade layers.

Specifications

Specification
CSS Cascading and Inheritance Level 4
CSS Cascading and Inheritance Level 5
CSS Cascading and Inheritance Level 6

See also