Use modular-css via postcss
npm install @modular-css/postcss@modular-css/postcss   
===========
PostCSS plugin to use modular-css within a PostCSS processor instance.
``bash`
> npm i @modular-css/postcss postcss
@modular-css/postcss provides a PostCSS plugin that can be used like any other. It will output a message with a type of modular-css-exports containing all the exported class compositions.
`js
const postcss = require("postcss");
const processor = postcss([
require("@modular-css/postcss")({
json : "./path/to/output.json"
})
]);
const result = await processor.process("
// result.css
// result.map
// result.messages.find((msg) => msg.type === "modular-css-exports")
// etc
`
`bash`
> postcss --config postcss.json input.css
`json
{
"output" : "out.css",
"@modular-css/postcss": {
"json" : "./path/to/output.json"
}
}
`
`bash`
> postcss --use modular-css/postcss input.css
Write the class composition data to this location on disk.
All other options are passed to the underlying Processor` instance, see Options.