[BUG] Polyfill doesn't handle Vite loading CSS files as JS

Describe the bug

I'm trying to install a css-anchor-positiong polyfill into my application and open it in safari.

I have this line in my application.js

if (!("anchorName" in document.documentElement.style)) {
  const { default: polyfill } = await import('@oddbird/css-anchor-positioning/fn');

  polyfill({
    elements: undefined,
    excludeInlineStyles: false,
    useAnimationFrame: false,
  });
}

This error occurs. Any advice on how to properly address it?

InvalidMimeType: Error loading http://localhost:3000/vite-dev/entrypoints/application.css: expected content-type "text/css", got "text/javascript".
(anonymous function) — fetch.ts:39
o — @oddbird_css-anchor-positioning_fn.js:23

vite.config.mjs

import { defineConfig } from 'vite'
import ViteRails from 'vite-plugin-rails'
import path from 'path' // Import 'path' for path resolution

const env = process.env.RAILS_ENV || 'development'

export default defineConfig({
  plugins: [
    ViteRails({
      fullReload: {
        additionalPaths: [
          'config/routes.rb',
          'app/views/**/*',
          'app/controllers/**/*',
          'app/models/**/*'
        ]
      }
    })
  ],
  define: {
    'process.env.RAILS_ENV': JSON.stringify(env)
  },
  resolve: {
    alias: {
      '@': path.resolve(__dirname, 'app/javascript')
    }
  }
})

Browsers tested on
Safari Version 18.3.1 (20620.2.4.11.6)

Start with the fetch.ts:39 stack-trace location and the Vite Rails setup shown in vite.config.mjs. Reproduce the Safari loading failure and trace why the CSS entrypoint is returned as JavaScript; done means the polyfill loads the stylesheet with the expected text/css content type.