Examine source code of DarkMode Plus

{
  "manifest_version": 3,
  "name": "DarkMode Plus",
  "version": "1.0.0",
  "description": "Cross-browser dark mode with immersive appearances.",
  "action": {
    "default_title": "DarkMode Plus",
    "default_popup": "popup.html"
  },
  "permissions": [
    "storage",
    "scripting",
    "tabs"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{d8c6da8f-0e08-4f92-94bb-c3f2d1a1b2c3}",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_start"
    }
  ],
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  }
}