Examine source code of Zenn Dark Theme

{
  "manifest_version": 2,
  "name": "Zenn Dark Theme",
  "description": "Zennのサイトをダークモードに変更するブラウザ拡張機能",
  "version": "0.1.0",
  "icons": {
    "16": "icon/16.png",
    "32": "icon/32.png",
    "48": "icon/48.png",
    "96": "icon/96.png",
    "128": "icon/128.png"
  },
  "permissions": [
    "",
    "*://*.zenn.dev/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "zenn-dark@hidaka.dev"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.zenn.dev/*"
      ],
      "css": [
        "content-scripts/content.css"
      ],
      "js": [
        "content-scripts/content.js"
      ]
    }
  ]
}