Examine source code of Leather

{
  "manifest_version": 3,
  "name": "Leather",
  "version": "1.2.0",
  "description": "A beautiful Firefox theme inspired by Leather, deep space and the endless cosmos.",
  "icons": {
    "48": "icons/48.png",
    "128": "icons/128.png"
  },
  "action": {
    "default_title": "Leather",
    "default_icon": {
      "48": "icons/48.png",
      "128": "icons/128.png"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "tabs"
  ],
  "host_permissions": [
    "https://guinkropla.pro/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "support-leather2@gmail.com",
      "strict_min_version": "109.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}