When I added the rules for node_modules in next.config.js, I encountered the issue of Built-in CSS support being disabled.

[Zzzccs123]

Link to the code that reproduces this issue

https://github.com/Zzzccs123/next-active-class-name-app

To Reproduce

// next.config.js

const nextConfig = {
  webpack: (config, { dev, defaultLoaders }) => {
    /* If execute it, an error will occur.  */
    // config.module.rules.push({
    //   test: /\.js|jsx$/,
    //   include: (modPath) => {
    //     return modPath.indexOf('node_modules') === -1
    //   },
    //   use: defaultLoaders.babel
    // });
    return config
  },
};

module.exports = nextConfig;

Both global.module.css and global.css are just regular CSS code.

// app/page.tsx
import Nav from "../components/Nav";
import './global.module.css'
import './global.css'

const IndexPage = () => (
  <>
    <Nav />
    <p>Hello, I'm the index page</p>
  </>
);

export default IndexPage;

Current vs. Expected behavior

I want to use babel-loader to transform the code in node_modules, aiming for compatibility with a wider range of browser versions.

So, I added rules for node_modules in next.config.js without modifying any css-related rules. However, I encountered an issue where Built-in CSS support is being disabled.

Exception Details:

Expected Behavior:
No errors will occur.

Provide environment information

Operating System:
  Platform: darwin
  Arch: arm64
  Version: Darwin Kernel Version 22.3.0: Mon Jan 30 20:39:46 PST 2023; root:xnu-8792.81.3~2/RELEASE_ARM64_T6020
  Available memory (MB): 32768
  Available CPU cores: 12
Binaries:
  Node: 18.19.1
  npm: 9.8.1
  Yarn: 1.22.22
  pnpm: 9.3.0
Relevant Packages:
  next: 15.1.6 // Latest available version is detected (15.1.6).
  eslint-config-next: N/A
  react: 18.3.1
  react-dom: 18.3.1
  typescript: 5.7.3
Next.js Config:
  output: N/A

Which area(s) are affected? (Select all that apply)

CSS

Which stage(s) are affected? (Select all that apply)

next build (local)

Additional context

No response