CSS Container Queries

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Geoff Graham on (Updated on )

The main idea of CSS Container Queries is to register an element as a “container” and apply styles to other elements when the container element meets certain conditions.

Container queries are often considered a modern approach to responsive web design where traditional media queries have long been the gold standard — the reason being that we can create layouts made with elements that respond to, say, the width of their containers rather than the width of the viewport.

.parent {
  container-name: hero-banner;
  container-type: inline-size;

  /* or container: hero-banner / inline-size; */
}

}

.child {
  display: flex;
  flex-direction: column;
}

/* When the container is greater than 60 characters... */
@container hero-banner (width > 60ch) {
  /* Change the flex direction of the .child element. */
  .child { 
    flex-direction: row;
  }
}

Why care about CSS Container Queries?

  1. When using a container query, we give elements the ability to change based on their container’s size, not the viewport.
  1. They allow us to define all of the styles for a particular element in a more predictable way.
  1. They are more reusable than media queries in that they behave the same no matter where they are used. So, if you were to create a component that includes a container query, you could easily drop it into another project and it will still behave in the same predictable fashion.
  1. They introduce new types of CSS length units that can be used to size elements by their container’s size.

Registering Elements as Containers

.cards {
  container-name: card-grid;
  container-type: inline-size;

  /* Shorthand */
  container: card-grid / inline-size;
}

This example registers a new container named card-grid that can be queried by its inline-size, which is a fancy way of saying its “width” when we’re working in a horizontal writing mode. It’s a logical property. Otherwise, “inline” would refer to the container’s “height” in a vertical writing mode.

  • The container-name property is used to register an element as a container that applies styles to other elements based on the container’s size and styles.
  • The container-type property is used to register an element as a container that can apply styles to other elements when it meets certain conditions.
  • The container property is a shorthand that combines the container-name and container-type properties into a single declaration.

Some Possible Gotchas

Querying a Container

@container my-container (width > 60ch) {
  article {
    flex-direction: row;
  }
}
  • The @container at-rule property informs the browser that we are working with a container query rather than, say, a media query (i.e., @media).
  • The my-container part in there refers to the container’s name, as declared in the container’s container-name property.
  • The article element represents an item in the container, whether it’s a direct child of the container or a further ancestor. Either way, the element must be in the container and it will get styles applied to it when the queried condition is matched.

Some Possible Gotchas

Container Queries Properties & Values

Container Queries Properties & Values

container-name

container-name: none | <custom-ident>+;
Value Descriptions
  • none: The element does not have a container name. This is true by default, so you will likely never use this value, as its purpose is purely to set the property’s default behavior.
  • <custom-ident>: This is the name of the container, which can be anything, except for words that are reserved for other functions, including defaultnoneatno, and or. Note that the names are not wrapped in quotes.
  • Initial value: none
  • Applies to: All elements
  • Inherited: No
  • Percentages: N/A
  • Computed value: none or an ordered list of identifiers
  • Canonical order: Per grammar
  • Animation: Not animatable

container-type

container-type: normal | size | inline-size;
Value Descriptions
  • normal: This indicates that the element is a container that can be queried by its styles rather than size. All elements are technically containers by default, so we don’t even need to explicitly assign a container-type to define a style container.
  • size: This is if we want to query a container by its size, whether we’re talking about the inline or block direction.
  • inline-size: This allows us to query a container by its inline size, which is equivalent to width in a standard horizontal writing mode. This is perhaps the most commonly used value, as we can establish responsive designs based on element size rather than the size of the viewport as we would normally do with media queries.
  • Initial value: normal
  • Applies to: All elements
  • Inherited: No
  • Percentages: N/A
  • Computed value: As specified by keyword
  • Canonical order: Per grammar
  • Animation: Not animatable

container

container: <'container-name'> [ / <'container-type'> ]?
Value Definitons

If <'container-type'> is omitted, it is reset to its initial value of normalwhich defines a style container instead of a size container. In other words, all elements are style containers by default, unless we explicitly set the container-type property value to either size or inline-size which allows us to query a container’s size dimensions.

  • Initial value: none / normal
  • Applies to: All elements
  • Inherited: No
  • Percentages: N/A
  • Computed value: As specified
  • Canonical order: Per grammar
  • Animation: Not animatable

Container Length Units

Container Width & Height Units

UnitNameEquivalent to…
cqwContainer query width1% of the queried container’s width
cqhContainer query height1% of the queried container’s height

Container Logical Directions

UnitNameEquivalent to…
cqiContainer query inline size1% of the queried container’s inline size, which is its width in a horizontal writing mode.
cqbContainer query block size1% of the queried container’s inline size, which is its height in a horizontal writing mode.

Container Minimum & Maximum Lengths

UnitNameEquivalent to…
cqminContainer query minimum sizeThe value of cqi or cqb, whichever is smaller.
cqmaxContainer query maximum sizeThe value of cqi or cqb, whichever is larger.

Container Style Queries

Container Style Queries is another piece of the CSS Container Queries puzzle. Instead of querying a container by its size or inline-size, we can query a container’s CSS styles. And when the container’s styles meet the queried condition, we can apply styles to other elements. This is the sort of “conditional” styling we’ve wanted on the web for a long time: If these styles match over here, then apply these other styles over there.

CSS Container Style Queries are only available as an experimental feature in modern web browsers at the time of this writing, and even then, style queries are only capable of evaluating CSS custom properties (i.e., variables).

Browser Support

The feature is still considered experimental at the time of this writing and is not supported by any browser, unless enabled through feature flags.

This browser support data is from Caniuse, which has more detail. A number indicates that browser supports the feature at that version and up.

Desktop

ChromeFirefoxIEEdgeSafari
129NoNo125TP

Mobile / Tablet

Android ChromeAndroid FirefoxAndroidiOS Safari
125No12518.0

Registering a Style Container

article {
  container-name: card;
}

That’s really it! Actually, we don’t even need the container-name property unless we need to target it specifically. Otherwise, we can skip registering a container altogether.

And if you’re wondering why there’s no container-type declaration, that’s because all elements are already considered containers. It’s a lot like how all elements are position: relative by default; there’s no need to declare it. The only reason we would declare a container-type is if we want a CSS Container Size Query instead of a CSS Container Style Query.

So, really, there is no need to register a container style query because all elements are already style containers right out of the box! The only reason we’d declare container-name, then, is simply to help select a specific container by name when writing a style query.

Using a Style Container Query

@container style(--bg-color: #000) {
  p { color: #fff; }
}

In this example, we’re querying any matching container (because all elements are style containers by default).

Notice how the syntax it’s a lot like a traditional media query? The biggest difference is that we are writing @container instead of @media. The other difference is that we’re calling a style() function that holds the matching style condition. This way, a style query is differentiated from a size query, although there is no corresponding size() function.

In this instance, we’re checking if a certain custom property named --bg-color is set to black (#000). If the variable’s value matches that condition, then we’re setting paragraph (p) text color to white (#fff).

Custom Properties & Variables

.card-wrapper {
  --bg-color: #000;
}
.card {
  @container style(--bg-color: #000) {
    /* Custom CSS */
  }
}

Nesting Style Queries

@container style(--featured: true) {
  article {
    grid-column: 1 / -1;
  }
  @container style(--theme: dark) {
    article {
      --bg-color: #000;
      --text: #fff;
    }
  }
}

Specification

CSS Container Queries are defined in the CSS Containment Module Level 3 specification, which is currently in Editor’s Draft status at the time of this writing.

Browser Support

Browser support for CSS Container Size Queries is great. It’s just style queries that are lacking support at the time of this writing.

  • Chrome 105 shipped on August 30, 2022, with support.
  • Safari 16 shipped on September 12, 2022, with support.
  • Firefox 110 shipped on February 14, 2023, with support.

This browser support data is from Caniuse, which has more detail. A number indicates that browser supports the feature at that version and up.

Desktop

ChromeFirefoxIEEdgeSafari
106110No10616.0

Mobile / Tablet

Android ChromeAndroid FirefoxAndroidiOS Safari
12512612516.0

Demos!

Many, many examples on the web demonstrate how container queries work. The following examples are not unique in that regard in that they illustrate the general concept of applying styles when a container element meets a certain condition.

You will find plenty more examples listed in the References at the end of this guide, but check out Ahmad Shadeed’s Container Queries Lab for the most complete set of examples because it also serves as a collection of clever container query use cases.

Card Component

In this example, a “card” component changes its layout based on the amount of available space in its container.

Call to Action Panel

This example is a lot like those little panels for signing up for an email newsletter. Notice how the layout changes three times according to how much available space is in the container. This is what makes CSS Container Queries so powerful: you can quite literally drop this panel into any project and the layout will respond as it should, as it’s based on the space it is in rather than the size of the browser’s viewport.

Stepper Component

This component displays a series of “steps” much like a timeline. In wider containers, the stepper displays steps horizontally. But if the container becomes small enough, the stepper shifts things around so that the steps are vertically stacked.

Icon Button

Sometimes we like to decorate buttons with an icon to accentuate the button’s label with a little more meaning and context. And sometimes we don’t know just how wide that button will be in any given context, which makes it tough to know when exactly to hide the icon or re-arrange the button’s styles when space becomes limited. In this example, an icon is displayed to the right edge of the button as long as there’s room to fit it beside the button label. If room runs out, the button becomes a square tile that stacks the icons above the label. Notice how the border-radius is set in container query units, 4cqi, which is equal to 4% of the container’s inline-size (i.e. width) and results in rounder edges as the button grows in size.

Pagination

Pagination is a great example of a component that benefits from CSS Container Queries because, depending on the amount of space we have, we can choose to display links to individual pages, or hide them in favor of only two buttons, one to paginate to older content and one to paginate to newer content.

Articles & Tutorials

General Information

Container Size Query Tutorials

Container Style Queries

References