Examine source code of meta CSS

{

  "manifest_version": 2,
  "version": "2021.2.25.1419",

  "default_locale": "en",

  "name": "meta CSS",
  "author": "Kodomobeya Oziisan",
  "description": "__MSG_description__",

  "browser_specific_settings": {
    "gecko": {
      "id": "{465e54c0-c503-41fa-9679-79a22710d673}",
      "strict_min_version": "86.0"
    }
  },

  "content_security_policy": "default-src 'none'; style-src 'self'; script-src 'self'",

  "permissions": [
    "file:///*",
    "http://*/*",
    "https://*/*",
    "storage",
    "tabs",
    "webNavigation"
  ],

  "background": {
    "page": "background.html"
  },

  // https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/manifest.json/browser_action
  "browser_action": {
    "browser_style": true
  },

  "sidebar_action": {
    "default_panel": "sidebar.html"
  },

  "options_ui": {
    "open_in_tab": true,
    "page": "options.html"
  },

  "commands": {
    "_execute_sidebar_action": {
      "suggested_key": { "default": "F2" },
      "description": "__MSG_commands__"
    }
  }

}