Examine source code of Focus Mode Toggle

{
  "manifest_version": 2,
  "name": "Focus Mode Toggle",
  "version": "1.0",
  "description": "Toggles a high-contrast focus mode (dark background) on the current webpage. Does not collect user data.",
  "permissions": [
    "activeTab"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "Toggle Focus Mode",
    "default_icon": {
      "16": "icons/icon16.png",
      "48": "icons/icon48.png"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      },
      "id": "{c50ab73f-0a50-4f9b-bd93-433ab9d89dca}"
    }
  }
}