<container-name>

A case-sensitive string that is used to identify the container.

The following conditions apply:

• The name can be any valid <custom-ident>, but must not equal default.
• The name value must not be in quotes.
• The dashed ident intended to denote author-defined identifiers (e.g., --container-name) is permitted.
• A list of multiple names separated by a space is allowed.

Given the following HTML example which is a card component with a title and some text:

<div class="card">
  <div class="post-meta">
    <h2>Card title</h2>
    <p>My post details.</p>
  </div>
  <div class="post-excerpt">
    <p>
      A preview of my <a href="https://example.com">blog post</a> about cats.
    </p>
  </div>
</div>

To create a containment context, add the container-type property to an element in CSS. The following example creates two containment contexts, one for the card meta information and one for the post excerpt:

.post-meta {
  container-type: inline-size;
}

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

Writing a container query via the @container at-rule will apply styles to the elements of the container when the query evaluates to true. The following example has two container queries, one that will apply only to the contents of the .post-excerpt element and one that will apply to both the .post-meta and .post-excerpt contents:

@container excerpt (min-width: 400px) {
  p {
    visibility: hidden;
  }
}

@container (min-width: 400px) {
  p {
    font-size: 2rem;
  }
}

For more information on writing container queries, see the CSS Container Queries page.

You can also provide multiple names to a container context separated by a space:

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

This will allow you to target the container using either name in the @container at-rule. This is useful if you want to target the same container with multiple container queries where either condition could be true:

@container meta (max-width: 500px) {
  p {
    visibility: hidden;
  }
}

@container card (max-height: 200px) {
  h2 {
    font-size: 1.5em;
  }
}

• CSS container queries
• @container at-rule
• CSS container shorthand property
• CSS container-type property
• CSS content-visibility property