update changelog

Author: RobinMalfait

CHANGELOG.md

@@ -16,6 +16,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Ensure fractional opacity modifiers work with named shadow sizes like `shadow-sm/12.5`, `text-shadow-sm/12.5`, `drop-shadow-sm/12.5`, and `inset-shadow-sm/12.5` ([#20302](https://github.com/tailwindlabs/tailwindcss/pull/20302))
 - Fix parsing selectors like `[data-foo]div` as one selector instead of two ([#20303](https://github.com/tailwindlabs/tailwindcss/pull/20303))
 - Fix stale `@tailwindcss/postcss` output when changed input CSS is passed from a preprocessor like Sass without updating the input file on disk ([#20310](https://github.com/tailwindlabs/tailwindcss/pull/20310))
+- Ensure CSS nesting is handled even when Lightning CSS isn't run, like in `@tailwindcss/browser` and Tailwind Play ([#20124](https://github.com/tailwindlabs/tailwindcss/pull/20124))
 
 ## [4.3.2] - 2026-06-26