Tailwindcss

The tailwindcss repo is a rust project because the repo contains toml file in the root folder.
Cargo aka config directs to members = ["crates/*"].

Crates

• ./node contains napi-template. napi compiles a nodejs addon from rust src.
• node crate has dependency to oxide crate.
• oxide depends on ignore and classification-macros crates.

So oxide obviously is main crate.

yarn build produces npm package with addon whose name depends on OS.

If to look at https://github.com/napi-rs you will see that the .\crates\node has similar properties. napi has napi-rs package-template for addon creation. To check, try creating a project as described in readme.md.

After clone and yarn install run npx napi rename --help. You will see that the command add the following :

• package name
• addon name
• repo url
• descrpiption

.\npm contains npm package configs for several OS.

Before building you need to add package yarn add @napi-rs/package-template, then to execute yarn build. A file with extension .node ,for instance myaddonwin32-x64-msvc.node, will appear in the root directory. It is your addon.
Run yarn test just in case.

I have node project with tailwind package.
When I install tailwindcss package, yarn/npm installes the package type that fits my OS. tailwindcss-oxide.win32-x64-msvc.node in my case.
The .\node_modules\@tailwindcss\oxide\index.js loads addon ./tailwindcss-oxide.win32-x64-msvc.node

 if (process.arch === 'x64') {
      try {
        return require('./tailwindcss-oxide.win32-x64-msvc.node')
      } catch (e) {
        loadErrors.push(e)
      }
      try {
        return require('@tailwindcss/oxide-win32-x64-msvc')
      } catch (e) {
        loadErrors.push(e)
      }

    }

and exports Scanner module.exports.Scanner = nativeBinding.Scanner

Conclusion
To understand properly how tailwindcss works you need to understand Rust code.

Using
This seems to be the most convenient approach for local use

1. npm install tailwindcss @tailwindcss/cli
2. add to empty ./input.css @import "tailwindcss";
3. create empty src/style.css
4. execute npx @tailwindcss/cli -i ./input.css -o ./src/style.css --watch
5. run on localhost any html with <link href="./style.css" rel="stylesheet">

The watch command assumes that if class list is changed in any file that references to style.css , then Tailwind CLI will parse the file and update styles.css