@container

Baseline Widely available *

This feature is well established and works across many devices and browser versions. It’s been available across browsers since ⁨February 2023⁩.

* Some parts of this feature may have varying levels of support.

The @container CSS at-rule is a conditional group rule that applies styles to a containment context. Style declarations are filtered by a condition and applied to the container if the condition is true. The condition is evaluated when the queried container size, <style-feature>, or scroll-state changes.

The container-name property specifies a list of query container names. These names can be used by @container rules to filter which query containers are targeted. The optional, case-sensitive <container-name> filters the query containers that are targeted by the query.

Once an eligible query container has been selected for an element, each container feature in the <container-condition> is evaluated against that query container.

Syntax

css

/* With a <size-query> */
@container (width > 400px) {
  h2 {
    font-size: 1.5em;
  }
}

/* With an optional <container-name> */
@container tall (height > 30rem) {
  p {
    line-height: 1.6;
  }
}

/* With a <scroll-state> */
@container scroll-state(scrollable: top) {
  .back-to-top-link {
    visibility: visible;
  }
}

/* With a <container-name> and a <scroll-state> */
@container sticky-heading scroll-state(stuck: top) {
  h2 {
    background: purple;
    color: white;
  }
}

/* Multiple queries in a single condition */
@container (width > 400px) and style(--responsive: true) {
  h2 {
    font-size: 1.5em;
  }
}

/* Condition list */
@container card (width > 400px), style(--responsive: true), scroll-state(stuck: top) {
  h2 {
    font-size: 1.5em;
  }
}

Parameters

<container-condition>

An optional <container-name> and a <container-query>. Styles defined in the <stylesheet> are applied if the condition is true.

<container-name>: Optional. The name of the container that the styles will be applied to when the query evaluates to true, specified as an <ident>.
<container-query>: A set of features that are evaluated against the query container when the size, <style-feature>, or scroll-state of the container changes.

Logical keywords in container queries

Logical keywords can be used to define the container condition:

and combines two or more conditions.
or combines two or more conditions.
not negates the condition. Only one 'not' condition is allowed per container query and cannot be used with the and or or keywords.

css

@container (width > 400px) and (height > 400px) {
  /* <stylesheet> */
}

@container (width > 400px) or (height > 400px) {
  /* <stylesheet> */
}

@container not (width < 400px) {
  /* <stylesheet> */
}

Named containment contexts

A containment context can be named using the container-name property.

css

.post {
  container-name: sidebar;
  container-type: inline-size;
}

The shorthand syntax for this is to use container in the form container: <name> / <type>, for example:

css

.post {
  container: sidebar / inline-size;
}

In container queries, the container-name property is used to filter the set of containers to those with a matching query container name:

css

@container sidebar (width > 400px) {
  /* <stylesheet> */
}

Details about usage and naming restrictions are described in the container-name page.

Descriptors

The <container-condition> queries include size and scroll-state container descriptors.

Size container descriptors

The <container-condition> can include one or more boolean size queries, each within a set of parentheses. A size query includes a size descriptor, a value, and — depending on the descriptor — a comparison operator. The queries always measures the content box as the comparison. The syntax for including multiple conditions is the same as for @media size feature queries.

css

@container (min-width: 400px) {
  /* … */
}
@container (orientation: landscape) and (width > 400px) {
  /* … */
}
@container (15em <= block-size <= 30em) {
  /* … */
}

aspect-ratio: The aspect-ratio of the container calculated as the width to the height of the container expressed as a <ratio> value.
block-size: The block-size of the container expressed as a <length> value.
height: The height of the container expressed as a <length> value.
inline-size: The inline-size of the container expressed as a <length> value.
orientation: The orientation of the container, either landscape or portrait.
width: The width of the container expressed as a <length> value.

Scroll-state container descriptors

Scroll-state container descriptors are specified inside the <container-condition> within a set of parentheses following the scroll-state keyword, for example:

css

@container scroll-state(scrollable: top) {
  /* … */
}
@container scroll-state(stuck: inline-end) {
  /* … */
}
@container scroll-state(snapped: both) {
  /* … */
}

Supported keywords for scroll-state container descriptors include physical and flow relative values

scrollable

Queries whether the container can be scrolled in the given direction via user-initiated scrolling, such as by dragging the scrollbar or using a trackpad gesture. In other words, is there overflowing content in the given direction that can be scrolled to? Valid scrollable values include the following keywords:

none: The container is not a scroll container or otherwise cannot be scrolled in any direction.
top: The container can be scrolled towards its top edge.
right: The container can be scrolled towards its right-hand edge.
bottom: The container can be scrolled towards its bottom edge.
left: The container can be scrolled towards its left-hand edge.
x: The container can be scrolled horizontally towards either or both of its left-hand or right-hand edges.
y: The container can be scrolled vertically towards either or both of its top or bottom edges.
block-start: The container can be scrolled towards its block-start edge.
block-end: The container can be scrolled towards its block-end edge.
inline-start: The container can be scrolled towards its inline-start edge.
inline-end: The container can be scrolled towards its inline-end edge.
block: The container can be scrolled in its block direction towards either or both of its block-start or block-end edges.
inline: The container can be scrolled in its inline direction towards either or both of its inline-start and inline-end edges.

If the test passes, the rules inside the @container block are applied to descendants of the scroll container.

To evaluate whether a container is scrollable, without being concerned about the direction, use the none value with the not operator:

css

@container not scroll-state(scrollable: none) {
  /* … */
}

snapped

Queries whether the container is going to be snapped to a scroll snap container ancestor along the given axis. Valid snapped values include the following keywords:

none: The container is not a scroll snap target for its ancestor scroll container. When implementing a snapped: none query, containers that are snap targets for the scroll container will not have the @container styles applied, whereas non-snap targets will have the styles applied.
x: The container is a horizontal scroll snap target for its ancestor scroll container, that is, it is snapping horizontally to its ancestor.
y: The container is a vertical scroll snap target for its ancestor scroll container, that is, it is snapping vertically to its ancestor.
block: The container is a block-axis scroll snap target for its ancestor scroll container, that is, it is snapping to its ancestor in the block direction.
inline: The container is an inline-axis scroll snap target for its ancestor scroll container, that is, it is snapping to its ancestor in the inline direction.
both: The container is both a horizontal and vertical scroll snap target for its ancestor scroll container and is snapping to its ancestor in both directions. The container won't match if it is only snapping to its ancestor along the horizontal or vertical axis. It needs to be both.

To evaluate a container with a non-none snapped scroll-state query, it must be a container with a scroll container ancestor having a scroll-snap-type value other than none. A snapped: none query will match even when there is no scroll container ancestor.

Evaluations occur when scrollsnapchanging events fire on the scroll snap container. If the test passes, the rules inside the @container block are applied to descendants of the container.

To evaluate whether a container is a snap target, without being concerned about the direction, use the none value with the not operator:

css

@container not scroll-state(snapped: none) {
  /* … */
}

stuck

Queries whether a container with a position value of