# parcel-bundler/lightningcss · RepoSense Release & Migration Intelligence

> Add support for `::highlight` by @lucasweng in #970. Drop-in upgrade. Migration: None.

## Metadata
- **Repository URL**: https://github.com/parcel-bundler/lightningcss
- **Primary Package**: `lightningcss` (NPM)
- **Categories**: `BUILD_TOOL`, `STYLING`
- **Latest Version**: `v1.33.0`
- **Semantic Status**: `COMPATIBLE`
- **Bundle Size Impact (unavailable)**: `Size Unavailable`
- **Atom Ingestion Feed**: https://github.com/parcel-bundler/lightningcss/releases.atom

## The Human Context (Plain-English Pitch)
lightningcss is an open-source library and developer tool in the parcel-bundler/lightningcss ecosystem. It saves developers from writing repetitive low-level boilerplate from scratch by providing a battle-tested, open-source implementation ready for production.

## Stage 1 Executive Summary ([Core Change] + [Required Action] + [Migration Effort])
Add support for `::highlight` by @lucasweng in #970. Drop-in upgrade. Migration: None.

## Breaking Changes & Required Actions
- Add support for `::highlight` by @lucasweng in #970
- Add support for @position-try at-rule by @mattcosta7 in #1238
- Add support for ::search-text and :current::search-text (#1212) by @lucinadin in #1213
- Collapse light-dark(x, x) to x by @cscnk52 in #1183

## Migration Snippet
```ts
npm install lightningcss@1.33.0
```

## Ecosystem Compatibility Matrix & Graph Warnings
- **TypeScript 5.x** [`COMPATIBLE`]: Ships standard TypeScript declaration files without type regressions.

## Zero-Noise Release Timeline
- **v1.33.0** (2026-07-20) [COMPATIBLE]: Add support for `::highlight` by @lucasweng in #970. Drop-in upgrade. Migration: None.

## Upgrade & Migration Q&A (GEO Direct Answers)
### Is parcel-bundler/lightningcss v1.33.0 safe to upgrade in production?
parcel-bundler/lightningcss v1.33.0 is classified as COMPATIBLE (MINOR release). Add support for `::highlight` by @lucasweng in #970. Drop-in upgrade. Migration: None.

### What breaking changes or compatibility risks exist in parcel-bundler/lightningcss v1.33.0?
No breaking API changes or peer dependency conflicts are recorded for parcel-bundler/lightningcss v1.33.0 in the RepoSense compatibility graph.

### What is the bundle size impact of lightningcss v1.33.0?
Measured bundle size telemetry is currently unavailable for lightningcss v1.33.0; verify build output locally before deploying.

### How do I upgrade lightningcss to v1.33.0?
Upgrade lightningcss to v1.33.0 by running "npm install lightningcss@1.33.0" and applying the migration steps: npm install lightningcss@1.33.0