Examine source code of Dark Mode Toggle

{
  "manifest_version": 2,
  "name": "Dark Mode Toggle",
  "version": "1.0",
  "permissions": [
    "storage",
    "tabs",
    "activeTab"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.top-nsi.fr/*"
      ],
      "css": [
        "darkmode.css"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{8b29a77b-4d80-4203-8442-f2a4aaba5038}"
    }
  }
}