.cluster-group {
  font-weight: 600;
  text-align: center;
  position: absolute;
  width: 20px;
  height: 20px;
}
.cluster-group > div {
  padding: 10px;
  background: #0094ff;
  color: #fff;
  display: inline-block;
  -moz-box-shadow: rgba(255, 255, 255, 0.3) 0 1px 0 inset, rgba(0, 0, 0, 0.0470588) 0 1px 2px;
  -webkit-box-shadow: rgba(255, 255, 255, 0.3) 0 1px 0 inset, rgba(0, 0, 0, 0.0470588) 0 1px 2px;
  box-shadow: rgba(255, 255, 255, 0.3) 0 1px 0 inset, rgba(0, 0, 0, 0.0470588) 0 1px 2px;
  -webkit-border-radius: 5em;
  -moz-border-radius: 5em;
  border-radius: 5em;
  opacity: .9;
}
.cluster-group > div > .static-content {
  position: absolute;
  background: none;
  bottom: 100%;
  left: 100%;
  width: 10em;
  display: inline-block;
  color: #000;
  -webkit-text-shadow: -1px -1px 0 #ffffff, 1px -1px 0 #ffffff, -1px 1px 0 #ffffff, 1px 1px 0 #ffffff;
  text-shadow: -1px -1px 0 #ffffff, 1px -1px 0 #ffffff, -1px 1px 0 #ffffff, 1px 1px 0 #ffffff;
  text-align: left !important;
}