Last week, I built a visual explainer of the CSS Cascade.
I used anchor positioning with chained anchors to stack the cascade steps. It worked, but Safari 26.4 and earlier had a bug with chained anchors, so I had to exclude Safari entirely via an @supports hack.
I wasn’t entirely happy with that, so I refactored the layout to use a subgrid based approach with grid-template-areas. Since subgrid became Baseline Widely Available recently, the timing also worked out.
While I was at it, I also restructured the HTML such that each cascade step is now a list item inside an ordered list, which gives better semantics.