I've recently read about and discussed CSS Scroll Snapping so often that I felt like I should build a CSS-only carousel based on it.
Here are a few things to note:
Accessibility is in line with all other CSS-only experiments: it can only be considered mediocre in term of semantics and visual indicators. Don't do this in production.
The going forward and back is done via a combination of CSS Scroll Snap together with scroll-behavior: smooth and moving the focus through the slides via anchor links.