Container queries case studies

Swetha Gopalakrishnan

Saurabh Rajpal

Container queries offer a highly dynamic and flexible approach to responsive design. Container queries use the @container at-rule. This works in a similar way to a media query with @media, but instead, @container queries a parent container for styling information rather than the viewport and user agent.

Container queries are part of Baseline Newly Available.

Browser Support

Source

By responding to the container size, container queries allow components to adapt to their location in an interface. For example, a card component can adapt its size and styles according to the container it's placed in, be it a sidebar, hero section, or a grid within the main body of a page.

As shown in the following illustration, you can combine media queries for macro layouts, container queries for micro layouts, with user-preference based media queries to create a powerful responsive design system. Read more about container queries and the new responsive design.

Image showing how different types of styling work together. — web.dev—The New Responsive.

This article is part of a series discussing how ecommerce companies enhanced their websites using new CSS and UI features. This time, we dive into how some companies used and benefited from container queries.

redBus

redBus maintains and serves different code for its mobile and desktop versions. After implementing container queries on their Things-to-do and cargo pages, they were able to unify this code into a single codebase for these sites. This made them responsive and saved development time. The following example demonstrates this using the cargo page:

Code

In the following example, .bpdpCardWrapper is the parent container, named as bpdpSection.

If the container bpdpSection has a minimum width of 744px, the font-size and line-height for the components selected by .bpdpCardContainer and .subTxt, .bpdpAddress is updated.

//Code for Container Queries
.bpdpCardWrapper {
   container-type: inline-size;
   container-name: bpdpSection;
}
@container bpdpSection (min-width: 744px){
   .bpdpCardContainer{
      font-size: 1rem;
      line-height: 1.5rem;
   }

   .subTxt, .bpdpAddress{
       font-size: 0.875rem;
       line-height: 1.25rem;
   }
}

Impact

	Before (multiple code base)	After (single code base)
Infrastructure	Separate infrastructure (high cost).	Same infrastructure (reduced cost).
Design	Separate UI but poor consistency.	Challenging to solve but possible.
Performance	Easy to handle as the system is separate but duplicates effort of improving performance.	This is page and feature specific but redBus PageSpeedInsights score is above 80.
Development	Separate developer teams.	30% - 40% reduction in time.

Tokopedia

Tokopedia's Product Detail Pages (PDP) contain multiple tabs for the shop and product information. Previously, the layout of this page was divided into three columns and sometimes the product name on the left was cut off for smaller screen sizes (see the following "Before" video).

To solve this layout problem, they easily and quickly adopted container queries. After this implementation, they were able to have a flexible layout where the product name was always fully visible (see the following "After" video).

Before

Before implementing container queries, the words "ISKU 10 in 1 Obeng satu.." on the top left are cut off for smaller screen sizes.

After

Implementing container queries adjusts the layout keeping the text within the viewport.

Code

The following code queries the size of the parent container named infowrapper. If the maximum width of the infowrapper is 360px, the child components' width, margin, and padding are adjusted.

Setting the container-type to inline-size queries the inline-direction size of the parent. In latin languages like English, this would be the width of the parent container, since the text flows inline from left to right.

export const styCredibilityContainer = css`
  container-name: infowrapper;
  container-type: inline-size;
`;

export const styBtnShopFollow = css`
  margin-left: auto;
  width: 98px;
  @container infowrapper (max-width: 360px) {
    width: 100%;
    margin-top: 2px;
    margin-bottom: 8px;
    padding-left: 60px;
  }
`;

export const styBottomRow = css`
  margin-top: 4px;
  padding-left: 60px;
  display: flex;
  align-items: center;

  @container infowrapper (max-width: 360px) {
    padding-left: 0px;
  }

  > div {
    text-align: left;
    margin-top: 0 !important;
  }
`;

Things to consider when using container queries

Tokopedia found their use case by looking out for text ellipsis on their site. This indicated containers that might be too small, causing the content to be cut off for the user.

Another good use case for container queries for ecommerce sites is to look out for reused components. For example, the Add to cart button might be shown differently based on the parent container (for example, only the icon if it's in the product card and icon with text if it's a primary CTA on the page). The button could be a good candidate for container queries.

You can choose to do incremental improvements to your site. For example, you could start with smaller use cases like the ellipse example from Tokopedia, and implement container queries there. Then, progressively find more cases and improve the CSS.

Resources:

Container queries land in stable browsers
Container queries-Designing in the Browser
Container query demos
Demo: container query cards
Video: What's new in Web UI - I/O 2023
Do you want to report a bug or request a new feature? We want to hear from you.

Explore the other articles in this series that talk about how ecommerce companies benefited from using new CSS and UI features such as Scroll-driven animations, popover, container queries and the has() selector.