Examine source code of Floating Music Window

{
  "manifest_version": 2,
  "name": "Floating Music Window",
  "version": "1.0",
  "description": "Control your music with a floating window in glassmorphism style",
  "permissions": [
    "activeTab",
    "tabs",
    "storage",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "styles.css"
      ]
    }
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "48": "icons/icon-48.png"
    }
  },
  "icons": {
    "48": "icons/icon-48.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{3acdb26c-eaf0-4ef2-a80e-989de0d74182}"
    }
  }
}