Examine source code of Dark Viewer

{
  "manifest_version": 2,
  "name": "Dark Mode Extension",
  "version": "1.1",
  "description": "A simple dark mode for websites",
  "permissions": [
    "activeTab",
    "storage",
    "<all_urls>"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icon.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "web_accessible_resources": [
    "popup.html"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{c27db854-75c4-4327-ab12-b3d44f7fb6d1}"
    }
  }
}