astro/.changeset/green-cups-hammer.md

astro
minor

Implements a new class-based scoping strategy

This implements the Scoping RFC, providing a way to opt in to increased style specificity for Astro component styles.

This prevents bugs where global styles override Astro component styles due to CSS ordering and the use of element selectors.

To enable class-based scoping, you can set it in your config:

import { defineConfig } from 'astro/config';

export default defineConfig({
  scopedStyleStrategy: 'class'
});

Note that the 0-specificity :where pseudo-selector is still the default strategy. The intent is to change 'class' to be the default in 3.0.