[css-pseudo-4] Enabling carousel design patterns in CSS

Carousels are an often used design pattern on the web. They are used in a variety of contexts, from product listing pages to slideshow like content. OpenUI has explored a range of carousel designs, showing that the specific layout and appearance can vary dramatically. They are also provided by many frameworks as components, however implementing a carousel correctly is complicated and often results in inconsistent and sometimes inaccessible implementations.

There are a variety of problems being solved by carousels, which we believe could be provided by a set of CSS features. Developers could then combine these CSS features to create the various designs. CSS-only component libraries could be built to further simplify this process.

I'd like to share a strawman set of feature proposals that enable the creation of a variety of carousel patterns out of plain HTML lists using CSS. I've put up an explainer with polyfills and demos (e.g. see the full carousel) where you can see the individual features and how they can be combined to make a full fledged CSS carousel. I'd like to introduce the problem, features and get feedback on the overall direction and where to take the discussion.

Explainer: https://github.com/flackr/carousel/

I'm adding this under css-pseudo-4 for now, but likely the features here would span css-grid-2, css-scroll-snap-2, and possibly other specs.

Read the linked explainer and its polyfill and demo examples, including the full carousel example, to understand the proposed feature set and how the patterns combine. The requested outcome is feedback on the overall direction and where discussion should go, but the issue names no specific implementation or test target.