Examine source code of Vidio Immersive Mode

{
  "manifest_version": 2,
  "name": "Vidio Immersive Mode",
  "version": "1.0.3",
  "description": "Browser extension for Vidio.com, watch Live and VOD content in windowed fullscreen mode",
  "short_name": "vidio immersive",
  "permissions": [
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{4862a698-8ad1-4ece-9316-63377147ae4c}"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.vidio.com/*"
      ],
      "css": [
        "vidio.immersive.css"
      ],
      "js": [
        "vidio.immersive.js"
      ],
      "run_at": "document_end"
    }
  ],
  "option_ui": {
    "page": "options.html",
    "browser_style": true
  },
  "background": {
    "scripts": [
      "vidio.immersive.service.js"
    ]
  }
}