Unable to use via ESM CDN like JSDelivr or JSPM

On JSDelivr it fails due to hard dependency on fs

await import("https://cdn.jsdelivr.net/npm/postcss-modules/+esm")
+esm:7 Uncaught Error: Failed to bundle using Rollup v2.79.1: the file imports a not supported node.js built-in module "fs". If you believe this to be an issue with jsDelivr, and not with the package itself, please open an issue at https://github.com/jsdelivr/jsdelivr

On JSPM which doesn't mind dependency to fs and can load postcss and sass due to it it fails due to an error in loader-utils subdepenendency.

await import('https://jspm.dev/postcss-modules');

npm:generic-names@4!cjs:1     GET https://jspm.dev/npm:loader-utils@3/lib/interpolateName!cjs net::ERR_ABORTED 404
Uncaught TypeError: Failed to fetch dynamically imported module: https://jspm.dev/postcss-modules

It would be really great to have it working at least on JSPM so that there's a way to bundle css modules in the browser using ESM/ImportMaps.

Start by tracing the package's browser import path and its dependencies on fs and loader-utils, using the JSDelivr and JSPM failures as reproduction cases. Check whether postcss-modules can load through JSPM and ESM without the loader-utils 404 or unsupported Node built-in error; done means browser-based CSS Modules bundling works through at least JSPM.