EuropaCSS native compiler — experimental preview

Compilation, migration analysis, and Studio need no Node, npm, Python, or Rust installation. Use the archive for your operating system and CPU. Linux GNU builds require the runner's glibc version or newer; these previews are not portable musl builds.

From this directory:

./europa examples/app.css --config examples/europa.json5 -o app.css --source-map
./europa examples/app.css --config examples/europa.json5 -o app.css --watch
./europa studio --config examples/europa.json5
./europa --help

On Windows use europa.exe. To compile your project, provide its entry stylesheet, JSON5 configuration, and output path. The output directory must already exist. The compiler resolves local imports and CSS packages through ancestor node_modules directories, including exports/style entries; it does not install dependencies or evaluate JavaScript configurations. Package metadata participates in watches and migration review snapshots.

Studio prints a local browser URL for live JSON5 typography, spacing, and grid previews. It can load project fonts from a sibling css/includes/fonts.css and public directory, or explicit --fonts / --public-dir paths. Export downloads your edits with comments intact; it does not overwrite the source config.

Native CSS nesting, non-media declaration order and contiguous named breakpoint ranges intentionally differ from legacy EuropaCSS. Common rules precede responsive rules within each scope; media retain their relative order and enclosing layers/conditions. Set nesting: 'expanded' in JSON5 to emit plain selector lists with per-branch specificity. The default is native. For a package whose old build appended all generated media globally, import one aggregate stylesheet with layer(name) and keep its component imports unlayered inside it. Before migrating an existing site, run:

./europa migrate path/to/app.css --from 1.0.0-beta.16 --config europa.json5 --json

Review findings and compare rendered pages. --fix rewrites supported suffix selectors; it never chooses a different appearance for you. Versioned migration analysis supports beta.6, beta.11 and beta.16, is bounded, and does not prove complete visual equivalence. Analyzer version 14 groups cross-selector risks by selector pair and prunes provably disjoint subjects. --budget N adjusts its comparison limit. responsiveOrder: 'generated-last' preserves authored media positions while appending directive media. migration: { mediaPacking: 'none' } disables speculative old-build media-packing checks when the old build did not pack media. Large reviews can use snapshot-bound receipts; see the migration guide before accepting a whole diagnostic code.

The optional europa compare command compares computed styles and element boxes on the same rendered DOM. It requires Node.js 22+ and an installed Chromium browser started with remote debugging; it downloads no browser and needs no npm packages. Supply the old/new compiled CSS and the URL of the stylesheet to replace:

./europa compare http://localhost:4000/admin --before old.css --after new.css --stylesheet /assets/admin.css --json

Run ./europa compare --help for CDP, viewport, and prepared-tab options. See docs/guide/compare.md in the source checkout for setup and coverage limits.

These archives are native beta build artifacts. They are unsigned and not notarized. manifest.json records target/toolchain details and file checksums. Cargo.lock, dependencies.json, and licenses/ record upstream versions and available notices. For crates that omit license files, versioned supplements record the upstream license source or declared license grant. dependencies.json also links each unmodified crate's source archive. Packaging fails if any notices are missing. The native npm workflow publishes tested platform packages, CLI and Vite adapter under the beta dist-tag for native-v* release tags.

Source and compiler documentation: https://github.com/brandocms/europacss

There is no standalone europa lint command. Compile to validate current CSS/config, or use migrate --check for versioned legacy checks. The optional Vite adapter is in the source checkout and runs this executable; it is not bundled as a Node binding. The source repository's docs/ directory contains the HTML documentation site.