npm i
npx parcel bundle bundle.js
This loads up tailwindcss/tailwind.css that comes with its npm package with the content of,
@tailwind base;
@tailwind components;
@tailwind utilities;
but this ends up having dist/bundle.css without parsing those directives.
Instead, by using a locally saved ./tailwind.css file with the exact same content and specifiying that instead in bundle.js, it gets parsed and produces a proper dist/bundle.css.