Examine source code of Toggle CSS

{
  "manifest_version": 2,
  "name": "Toggle CSS",
  "version": "1.0",
  "description": "Easily toggle CSS styles on and off for the current webpage.",
  "permissions": [
    "activeTab"
  ],
  "browser_action": {
    "default_icon": "icons/toggle-css-48.png",
    "default_popup": "popup.html",
    "default_title": "Toggle CSS"
  },
  "icons": {
    "48": "icons/toggle-css-48.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{443f7782-3f45-447e-82fc-1ac800037fb0}"
    }
  }
}