Examine source code of Overleaf Dark Mode

{
  "name": "Overleaf Dark Mode",
  "version": "0.0.1",
  "manifest_version": 2,
  "description": "hacky implementation of a dark mode for Overleaf",
  "icons": {
    "16": "icon16.png",
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "content_scripts": [
    {
      "matches": [
        "https://*.overleaf.com/project/*"
      ],
      "css": [
        "styles.css"
      ],
      "js": [
        "overleaf.js"
      ],
      "run_at": "document_end"
    }
  ],
  "browser_action": {
    "default_title": "Overleaf Dark Mode"
  }
}