openlayers_behavior_fullscreen.css in Openlayers 6.2

.openlayers_map_fullscreen {
  position: fixed;
  z-index: 9999;
  background-color: #fff;
  top: 0;
  left: 0;
  height: 100% !important;
  width: 100% !important;
  }

.openlayers_behavior_fullscreen_button_panel {
  position: absolute;
  top: 5px;
  right: 5px;
  }

.openlayers_behavior_fullscreen_buttonItemInactive {
  background:url(openlayers_behavior_fullscreen.png);
  width:20px;
  height:20px;
  }
 
.openlayers_map_fullscreen .openlayers_behavior_fullscreen_buttonItemInactive {
  background-position:20px 0;
  }