Overview

One utility, in its own layer.

Why it is not a component

.scrollsnap changes the grid-template-columns that a component such as .items declares for itself in @layer components. A later layer beats an earlier one regardless of specificity, so putting it in @layer utilities is what lets a single class opt an existing component into carousel behaviour without rewriting the component.

That is also the test for anything else that might land here: a utility is a modifier applied to something else, not a thing of its own. If it has its own markup, it is a component.

@layer utilities must come last in your layer declaration for this to hold. See Cascade layers.