At-rules
At-rules are CSS statements that instruct CSS how to behave. They begin with an at sign, '@
' (U+0040 COMMERCIAL AT
), followed by an identifier, and include everything up to the next semicolon, ';
' (U+003B SEMICOLON
), or the next CSS block, whichever comes first.
Syntax
Statement at-rules
/* General structure */
@identifier (RULE);
/* Example: tells browser to use UTF-8 character set */
@charset "utf-8";
Statement at-rules end in a semicolon. There are several statement at-rules, designated by their identifiers, each with a different syntax:
- {{cssxref("@charset")}}
- : An algorithm (has the syntactic form of an at-rule, but isn't a definition) that determines the fallback character set used by the style sheet (CSS Syntax).
- {{cssxref("@import")}}
- : Tells the CSS engine to include an external style sheet (CSS cascade and inheritance).
- {{cssxref("@layer")}}
- : Defines the order of precedence in case of multiple cascade layers (CSS cascade and inheritance). Also used as a block at-rule to define a layer's styles.
- {{cssxref("@namespace")}}
- : Defines a default namespace for a style sheet or a namespace prefix that a selector only matches if the namespace and other selector components match (CSS namespaces).
Block at-rules
@identifier (RULE) {
}
Block at-rules end in a {}
-block that contain nested rules, other at-rules, or property or descriptor declarations.
- {{cssxref("@counter-style")}}
- : Define custom counter styles and extend predefined list styles (CSS counter styles).
- {{cssxref("@container")}}
- : A conditional group rule that applies its content if the container meets the
<container-condition>
s (CSS containment).
- : A conditional group rule that applies its content if the container meets the
- {{cssxref("@font-face")}}
- : Defines font resource locations, both local and external, along with the style characteristics for when those resources are used with a declared {{cssxref("font-family")}} (CSS fonts).
- {{cssxref("@font-feature-values")}} (plus
@swash
,@ornaments
,@annotation
,@stylistic
,@styleset
and@character-variant
)- : Controls font display per font-family by defining font-specific alternates, or custom names, to feature indexes in {{cssxref("font-variant-alternates")}} in OpenType (CSS fonts).
- {{cssxref("@keyframes")}} (and the
@-webkit-keyframes
alias)- : Define a named animation by describing defining CSS styles for intermediate steps (or keyframes) in the animation sequence (CSS animations).
- {{cssxref("@layer")}}
- : Creates a named cascade layer with the CSS rules for that layer inside (CSS cascade and inheritance). Also used as a statement at-rule to define the order of precedence in case of multiple cascade layers
- {{cssxref("@media")}}
- : A conditional group rule that applies its content if the device meets the criteria of the condition defined using a media query (CSS conditional rules).
- {{cssxref("@page")}}
- : Specifies aspects of a page to be printed, such as its dimensions, orientation, and margins (CSS paged media).
- {{cssxref("@position-try")}}
- : Defines custom position options which can be used to define fallback positioning and alignment options for anchor-positioned elements (CSS anchor positioning).
- {{cssxref("@property")}}
- : Defines a CSS custom property, allowing for property type checking and constraining, setting default values, and defining whether a custom property can inherit values or not (CSS custom properties for cascading variables).
- {{cssxref("@scope")}}
- : Defines a scope in which to apply them to selected elements and the styles to apply to the elements in that scope (CSS cascade and inheritance).
- {{cssxref("@starting-style")}}
- : Define the starting property values for an element to transition from when the element receives its first style update, such as when transitioning from
display: none
(CSS transitions).
- : Define the starting property values for an element to transition from when the element receives its first style update, such as when transitioning from
- {{cssxref("@supports")}}
- : A conditional group rule applies its content if the browser supports the CSS features of the given condition (CSS conditional rules).
- {{cssxref("@view-transition")}}
- : Opts the current document into a view transition, and the destination document as well in the case of cross-document navigation transitions.
Index
- {{cssxref("@charset")}}
- {{cssxref("@color-profile")}}
- {{cssxref("@container")}}
- {{cssxref("@counter-style")}}
- {{cssxref("@font-face")}}
- {{cssxref("@font-feature-values")}}
- {{cssxref("@font-palette-values")}}
- {{cssxref("@import")}}
- {{cssxref("@keyframes")}}
- {{cssxref("@layer")}}
- {{cssxref("@media")}}
- {{cssxref("@namespace")}}
- {{cssxref("@page")}}
- {{cssxref("@position-try")}}
- {{cssxref("@property")}}
- {{cssxref("@scope")}}
- {{cssxref("@starting-style")}}
- {{cssxref("@supports")}}
- {{cssxref("@view-transition")}}