11ai Tailwind CSS v4 builds and sources

Version baseline: Tailwind CSS 4.3.1 (stable), verified 2026-07-31; align official adapters to v4.3 and use v4 source directives.

Resolve the active adapter, CSS entry, automatic source base, ignored paths, explicit sources, command, output owner, and browser target before running or changing a build.

Inspect first

npm ls tailwindcss @tailwindcss/vite @tailwindcss/postcss @tailwindcss/cli @tailwindcss/webpack --depth=0
rg -n 'tailwindcss|@tailwindcss/|@import "tailwindcss"|@source' package.json --glob '*.css' --glob '*config*'
git check-ignore -v SOURCE_FILE

Count authored files added by each explicit source. Distinguish source trees from generated output, dependencies, binary files, and package-manager stores.

Operate

Use the existing adapter. Adjust source() on the import or add a narrow @source only when automatic detection demonstrably misses an owned source. Use @source not for a known over-broad subtree and @source inline() only for bounded external class contracts.

npx @tailwindcss/cli -i INPUT.css -o TEMP_OUTPUT.css --minify

Run this only when the aligned CLI adapter is installed. Compile to a disposable path before replacing output. Watch mode creates a long-running process; start and stop it only on request.

Verify and report

Confirm representative base, utility, custom, responsive, state, and explicitly sourced selectors, run the production build, and compare output bytes and build time. Report adapter, paths, source counts, ignore evidence, command, exit code, selector evidence, size change, browser assumptions, files, and rollback. Ask before overwriting committed or deployed CSS.