#taskmenu a.button-mailu {
  background: url('/static/mailu.png');
  background-repeat: no-repeat;
  background-position: center;
  background-position-y: 6px;
  background-size: 22px 22px;
}
#taskmenu a.button-mailu.selected, #taskmenu a.button-mailu.selected:hover, #taskmenu a.button-mailu:hover {
  color: #fff;
  background-color: #45555c;
}