Examine source code of GAS Dark Mode

{
  "manifest_version": 3,
  "name": "GAS Dark Mode",
  "version": "2.2",
  "description": "Uses the official Dark Reader headless API and css file to cover for it",
  "permissions": [
    "storage"
  ],
  "action": {
    "default_title": "Toggle Dark Mode"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "gas-dark-mode@local-machine.net",
      "strict_min_version": "109.0"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "https://script.google.com/*",
        "https://ogs.google.com/*"
      ],
      "css": [
        "styles.css"
      ],
      "js": [
        "darkreader.js",
        "init.js"
      ],
      "run_at": "document_start",
      "all_frames": true,
      "match_about_blank": true
    }
  ]
}