Examine source code of Dark Mode

{
  "name": "Dark Mode",
  "description": "Dark Theme For Websites",
  "version": "1.0.3",
  "permissions": [
    "activeTab"
  ],
  "background": {
    "scripts": [
      "bg.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*"
      ],
      "css": [
        "css.css"
      ]
    }
  ],
  "manifest_version": 2
}