I was messing about with some images on a website recently and while I was happy enough with the arrangement on large screens, I thought it would be better to have the images in a kind of carousel on smaller screens—a swipable gallery. My old brain immediately thought this would be fairly complicated to do, but actually it’s ludicrously straightforward. Just stick this bit of CSS on the containing element inside a media query (or better yet, a container query): display: flex; overflow-x: ...
