Examine source code of GPThemes - ChatGPT Customization

{
  "manifest_version": 2,
  "version": "6.4.0",
  "name": "GPThemes - ChatGPT Widescreen, Fonts & Color",
  "description": "Redesign ChatGPT: custom color, fonts & layouts — widescreen mode, chat bubbles, expandable chatbox, hide header/footer & more",
  "author": "itsmarta",
  "homepage_url": "https://github.com/itsmartashub/GPThemes",
  "icons": {
    "16": "16.553615da.png",
    "48": "48.f12e30ca.png",
    "128": "128.6689033b.png"
  },
  "content_scripts": [
    {
      "matches": [
        "https://chat.openai.com/*",
        "https://chatgpt.com/*"
      ],
      "js": [
        "content.600bf6ce.js",
        "content.e6a1ab15.js"
      ],
      "css": [
        "sass.f26be563.css"
      ],
      "run_at": "document_idle"
    }
  ],
  "permissions": [
    "storage",
    "https://chat.openai.com/*",
    "https://chatgpt.com/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "gpthemes@itsmarta",
      "strict_min_version": "128.0"
    }
  },
  "background": {
    "scripts": [
      "background.0ba7c36e.js"
    ],
    "persistent": false
  },
  "content_security_policy": "script-src 'self'; style-src 'self' https://fonts.googleapis.com; font-src 'self' https://fonts.gstatic.com;",
  "browser_action": {
    "default_popup": "popup.27e0471e.html",
    "default_icon": {
      "16": "16.553615da.png",
      "48": "48.f12e30ca.png",
      "128": "128.6689033b.png"
    },
    "default_title": "ChatGPT Widescreen, Custom Fonts & Color"
  }
}