Examine source code of Onliness

{
  "manifest_version": 3,
  "name": "Onliness",
  "version": "1.0.2",
  "description": "Turns website dark when the internet connection is not available.",
  "browser_specific_settings": {
    "gecko": {
      "id": "onliness@defiantware",
      "strict_min_version": "109.0"
    }
  },
  "icons": {
    "16": "icons/onliness-icon-16x16.png",
    "32": "icons/onliness-icon-32x32.png",
    "48": "icons/onliness-icon-48x48.png",
    "128": "icons/onliness-icon-128x128.png"
  },
  "permissions": [
    "activeTab"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "css": [
        "style.css"
      ],
      "js": [
        "content.js"
      ]
    }
  ]
}