.leaflet-control-centermarker a {
  background:#fff url(centermark.png) no-repeat 0 0;
  background-size:26px 26px;
  }
  .leaflet-touch .leaflet-control-centermarker a {
    background-position: 2px 2px;
    }
@media
  (-webkit-min-device-pixel-ratio:2),
  (min-resolution:192dpi) {
    .leaflet-control-centermarker a {
      background-image:url(centermark@2x.png);
    }
  }