.leaflet-control-defaultextent {
  position:fixed;
  top:-40px;
}

.leaflet-control-defaultextent-toggle {
  text-indent:-9999px;
  white-space:nowrap;
  background-image:url('../css/images/leaflet.defaultextent.png');
  width:26px;
  height:26px;
  display:block;
}

/* CSS for high-resolution devices */
@media only screen and (-Webkit-min-device-pixel-ratio: 1.5),
only screen and (-moz-min-device-pixel-ratio: 1.5),
only screen and (-o-min-device-pixel-ratio: 3/2),
only screen and (min-device-pixel-ratio: 1.5) {
    .leaflet-control-defaultextent-toggle {
        background-image:url('images/leaflet.defaultextent@2X.png');
        background-size:26px 26px;
        background-repeat:no-repeat;
    }
}