Examine source code of Spectrum

{
  "manifest_version": 3,
  "name": "Spectrum",
  "version": "1.5.2",
  "description": "__MSG_extDesc__",
  "default_locale": "en",
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "https://spectr39s.ru/*"
      ],
      "js": [
        "js/main.js"
      ],
      "css": [
        "css/fixes.css"
      ],
      "run_at": "document_start"
    }
  ],
  "web_accessible_resources": [
    {
      "resources": [
        "css/*.css",
        "icons/*.svg"
      ],
      "matches": [
        "https://spectr39s.ru/*"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "spectrum@spectr39s.ru"
    },
    "gecko_android": {
      "id": "spectrum@spectr39s.ru"
    }
  }
}