Changelog

2026-05-14

Added reference page and explanation page for the new apps/frontend/src/lib/matched-rules library — the in-page primitive that returns every CSS rule affecting a DOM element in the preview iframe, with source positions, specificity, and cascade-aware ordering. Foundation for the upcoming Styles inspector panel.
Added the first ADR — ADR-0001: Matched-rules library is in-page and uses lightningcss-wasm — recording why we chose an in-page implementation over a DevTools Protocol bridge, why lightningcss-wasm over CSSOM / a hand-written parser, and the matcher/cascade split. Removed the “no ADRs yet” placeholder from the ADR index.

Added an explanation of the StyleController’s Classes component — covers the multi-select intersection rule, the deliberate replace vs replaceAll split between remove and rename, and the ActionManager do/reverse payload pattern.