Examine source code of Ecosia Dark Mode

{
  "name": "Ecosia Darkmode",
  "description": "Browse Ecosia in dark mode - save the planet, and your eyes.",
  "version": "1.574",
  "author": "Kw_hrs",
  "manifest_version": 2,
  "icons": {
    "16": "/images/get_started16.png",
    "32": "/images/get_started32.png",
    "48": "/images/get_started48.png",
    "128": "/images/get_started128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "https://www.ecosia.org/*"
      ],
      "css": [
        "dark.css"
      ],
      "run_at": "document_start"
    },
    {
      "matches": [
        "https://info.ecosia.org/*"
      ],
      "css": [
        "dark_info.css"
      ],
      "run_at": "document_start"
    }
  ],
  "permissions": [],
  "browser_specific_settings": {
    "gecko": {
      "id": "{f8f2ca66-b8f1-4c77-87d6-2825797a79f0}"
    }
  }
}