Custom sites

manifest.json

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "name": "Custom sites",
  "description": "create a website style",
  "version": "4.1",
  "manifest_version": 3,
  "background": {
    "service_worker": "background.js"
  },
  "icons": {
    "48": "image 3.png"
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "contentscript.js"
      ]
    }
  ],
  "permissions": [
    "storage",
    "activeTab"
  ],
  "action": {
    "default_popup": "popup.html"
  },
  "host_permissions": [
    "*://*.google.com/"
  ]
}