This section describes Cascading Style Sheets (CSS) at-rules. At-rules start with an at-keyword (an '@' character followed immediately by an identifier), and consist of everything up to and including the next semicolon (;) or declaration block, whichever comes first.

In this section



Sets the character set for an external style sheet.


Sets a font to embed in the HTML document.


Imports an external style sheet.


Sets the media types for a set of rules in a styleSheet object.


Specifies a list of property animation keyframes for an object in the HTML document.


Specifies properties that describe the viewport.


Declares an XML namespace (and, optionally, its prefix) and associates it with a string that represents a namespace name.


Sets the dimensions, orientation, and margins of a page box in a styleSheet.


Specifies CSS to be conditioned on browser support of the feature.