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

.tabbrowser-tab {
  margin-top: 0 !important;
}
.tabs-stack {
  display: none;
}

.tabbrowser-tab[selected="true"] {
  background-clip: border-box !important;
  background-image: -moz-linear-gradient(rgba(255,255,255,0) 50%, rgba(255,255,255,0.5) 65%),
                    -moz-linear-gradient(rgba(255,255,255,0) 30%, -moz-dialog 65%) !important;
}