#navigator-throbber
  {
    list-style-image      : url("chrome://global/skin/animthrob_single.gif");
    min-width             : 36px;
    min-height            : 36px;
    vertical-align        : middle;
    padding               : 1px;
    margin                : 2px 4px 2px 1px;
    border                : none;
    cursor                : pointer;
  }  

#navigator-throbber[busy="true"]
  {
    list-style-image      : url("chrome://global/skin/animthrob.gif");
  }
  
#navigator-throbber:hover:active
  {
    padding               : 2px 0px 0px 2px;
  }

#navigator-throbber > .button-internal-box
  {
    border                : 1px solid transparent;
    padding               : 0px;
  }

#navigator-throbber:hover > .button-internal-box
  {
    border                : 1px outset #CCD0DD;
  }

#navigator-throbber:hover:active > .button-internal-box
  {
    border                : 1px inset #CCD0DD;
  }

#navigator-throbber > .button-internal-box > .button-text-container
  {
    display               : none;
  }