Can We Create a “Resize Hack” With Container Queries?

So, what is a container query? It’s… exactly that. Much like we have media queries for querying things such as the viewport size, a container query allows us to query the size of a container. Based on that, we can then apply different styles to the children of said container.

What does it look like? Well, the exact standards are being worked out. Currently, though, it’s something like this:

.container {
  contain: layout size;
  /* Or... */
  contain: layout inline-size;
}

@container (min-width: 768px) {
  .child { background: hotpink; }
}

The layout keyword turns on layout-containment for an element. inline-size allows users to be more specific about containment. This currently means we can only query the container’s width. With size, we are able to query the container’s height.

Again, we things could still change. At the time of writing, the only way to use container queries (without a polyfill) is behind a flag in Chrome Canary (chrome://flags). I would definitely recommend having a quick read through the drafts over on csswg.org.

Try changing the contain values (in Chrome Canary) and see how the demos respond. These demo uses contain: layout size which doesn’t restrict the axis. When both the height and width of the containers meet certain thresholds, the shirt sizing adjusts in the first demo. The second demo shows how the axes can work individually instead, where the beard changes color, but only when adjusting the horizontal axis.

@container (min-width: 400px) and (min-height: 400px) {
  .t-shirt__container {
    --size: "L";
    --scale: 2;
  }
}

That’s what you need to know to about container queries for now. It’s really just a few new lines of CSS.

The only thing is: most demos for container queries I’ve seen so far use a pretty standard “card” example to demonstrate the concept. Don’t get me wrong, because cards are a great use case for container queries. A card component is practically the poster child of container queries. Consider a generic card design and how it could get affected when used in different layouts. This is a common problem. Many of us have worked on projects where we wind up making various card variations, all catering to the different layouts that use them.

But cards don‘t inspire much to start playing with container queries. I want to see them pushed to greater limits to do interesting things. I‘ve played with them a little in that t-shirt sizing demo. And I was going to wait until there was better browser support until I started digging in further (I’m a Brave user currently). But then Bramus shared there was a container query polyfill!