Examine source code of Audible Dark Theme

{
  "manifest_version": 2,
  "name": "Audible Dark Theme",
  "version": "1.0.2",
  "description": "Adds a dark theme to the Audible Website and Webplayer.",
  "icons": {
    "48": "icons/audible-dark.png"
  },
  "content_scripts": [
    {
      "matches": [
        "https://*.audible.co.uk/*",
        "https://*.audible.com/*",
        "https://*.audible.de/*",
        "https://*.audible.ca/*",
        "https://*.audible.com.au/*",
        "https://*.audible.co.jp/*",
        "https://*.audible.fr/*",
        "https://*.audible.es/*",
        "https://*.audible.force.com/*",
        "https://*.audible.in/*",
        "https://*.audible.it/*"
      ],
      "js": [
        "js/jquery.min.js",
        "js/script.js"
      ],
      "css": [
        "css/style.css"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{d8c4add0-55bd-4315-94c9-e7775c6aabc3}"
    }
  }
}