Examine source code of Reddit Auto Theme

{
  "manifest_version": 3,
  "name": "Reddit Auto Theme",
  "version": "1.4",
  "description": "Automatically applies the dark or light theme on Reddit based on the system theme.",
  "permissions": [
    "storage"
  ],
  "host_permissions": [
    "*://www.reddit.com/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://www.reddit.com/*"
      ],
      "js": [
        "content-script.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "action": {
    "default_icon": {
      "16": "icons/icon-16.png",
      "32": "icons/icon-32.png"
    },
    "default_title": "Reddit Auto Theme"
  },
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "reddit-auto-theme@eucaue"
    }
  }
}