Examine source code of CSS Viewer

{
  "manifest_version": 2,
  "name": "CSS Viewer",
  "version": "1.0.0",
  "description": "Inspect CSS properties of elements by hovering over them.",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "CSS Viewer",
    "default_popup": "popup.html"
  },
  "permissions": [
    "activeTab"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "cssviewer-0fb9lv@example.com",
      "strict_min_version": "109.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}