Examine source code of Focus Filter Suite

{
  "manifest_version": 3,
  "name": "Focus Filter Suite",
  "version": "2.7.0",
  "description": "Combines YouTube, Reddit, Instagram, and general Web focus filtering into one extension, with every structural block individually toggleable. Any settings change that loosens restriction is delayed by a user-set period before it takes effect; tightening changes are always instant. Works on desktop and Firefox for Android.",
  "permissions": [
    "storage",
    "alarms"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "https://www.youtube.com/*",
        "https://m.youtube.com/*"
      ],
      "js": [
        "content-youtube.js"
      ],
      "css": [
        "content-youtube.css"
      ],
      "run_at": "document_start"
    },
    {
      "matches": [
        "https://www.reddit.com/*",
        "https://old.reddit.com/*"
      ],
      "js": [
        "content-reddit.js"
      ],
      "css": [
        "content-reddit.css"
      ],
      "run_at": "document_start"
    },
    {
      "matches": [
        "https://www.instagram.com/*",
        "https://instagram.com/*"
      ],
      "js": [
        "content-instagram.js"
      ],
      "css": [
        "content-instagram.css"
      ],
      "run_at": "document_start"
    },
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content-web.js"
      ],
      "css": [
        "content-web.css"
      ],
      "run_at": "document_start"
    }
  ],
  "action": {
    "default_icon": {
      "16": "icons/icon16.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "options_ui": {
    "page": "options.html",
    "open_in_tab": true
  },
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "focus-filter-suite@local.extension",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": [
          "websiteContent"
        ]
      }
    },
    "gecko_android": {
      "strict_min_version": "140.0"
    }
  }
}