Hovern über einen Link produziert keine Einblendung

/* Statusleiste für Firefox */

// https://www.camp-firefox.de/forum/viewtopic.php?p=1052187&sid=d4e33b574226439c26dfb45629b71369#p1052187
// entwickelt von aborix 

(function() {
	    if (location.href !== 'chrome://browser/content/browser.xhtml') return;

 // if (location != AppConstants.BROWSER_CHROME_URL) return;
  
  var css =`
    #new-toolbar {
        height: 28px; 
        direction: rtl;
        -moz-window-dragging: no-drag; 
         border-top: 1px solid black !important; 
        background-color: rgba(0,0,0,0) !important;
        color: black !important; 
    } 
    
    #statuspanel {
        bottom: -3px !important;
        left: 0 !important;
        height: 24px !important;
        max-width: 75% !important;
        transition: none !important;
    }
    
    #statuspanel-label{
        background:#7598ff!important;
        border: none !important;
        font: 17px Arial Rounded MT Bold !important;
        font-weight: normal !important;
        color: black !important;
    }
  `;
  
  var sss = Cc['@mozilla.org/content/style-sheet-service;1'].getService(Ci.nsIStyleSheetService);
  var uri = makeURI('data:text/css;charset=UTF=8,' + encodeURIComponent(css));
  sss.loadAndRegisterSheet(uri, sss.AUTHOR_SHEET);
  
  var tb = document.createXULElement('toolbar');
  tb.id = 'new-toolbar';
  tb.setAttribute('customizable', true);
  tb.setAttribute('mode', 'icons');
  tb.setAttribute("context","toolbar-context-menu");
  var vbox  = document.createXULElement('vbox');
  document.getElementById('navigator-toolbox').parentNode.insertBefore(
  vbox, document.getElementById('browser-bottombox'));
  vbox.style.backgroundColor = '#ffe4c4';
  vbox.appendChild(tb);

  CustomizableUI.registerArea('new-toolbar', {legacy: true});
  CustomizableUI.registerToolbarNode(tb);  
   
})();