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

If you follow new developments in CSS, you’ve likely heard of the impending arrival of container queries. We’re going to look at the basics here, but if you’d like another look, check out Una’s “Next Gen CSS: @container” article. After we have a poke at the basics ourselves, we’re going to build something super fun with them: a fresh take on the classic CSS meme featuring Peter Griffin fussing with window blinds. ;)

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…