{
  "prefbar:info": {
    "formatversion": 3
  },
  "prefbar:menu:enabled": {
    "items": [
      "prefbar:button:togglecss"
    ]
  },
  "prefbar:button:togglecss": {
    "type": "extcheck",
    "label": "CSS (Tab)",
    "setfunction": "getBrowser().markupDocumentViewer.authorStyleDisabled = !value;",
    "getfunction": "value = !getBrowser().markupDocumentViewer.authorStyleDisabled;",
    "browserbtnupdatefor": "tab"
  }
}