@namespace url(http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul);

tab .tab-progress{
   -moz-appearance: none !important;
   background-color: transparent !important; }
tab .progress-bar{
   background-color: rgb(170,170,255) !important;
   margin-top: 1px !important; 
   margin-bottom: -1px !important;  
  -moz-appearance: none  !important; }