Examine source code of Page Styler

{
  "manifest_version": 2,
  "name": "Page Styler",
  "version": "1.0",
  "description": "Modify the appearance of a webpage by changing the background color and font size.",
  "icons": {
    "48": "icon.png"
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icon.png"
  },
  "permissions": [
    "activeTab"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{2c662dab-947a-4796-9672-0efc682f1757}"
    }
  }
}