body {
  text-align: center;
}
.gmap3{
  margin: 20px auto;
  border: 1px dashed #C0C0C0;
  width: 1000px;
  height: 500px;
}
.cluster{
  color: #FFFFFF;
  text-align:center;
  font-family: 'Arial, Helvetica';
  font-size:11px;
  font-weight:bold;
  cursor: pointer;
}
.cluster-1{
  background-image:url(images/m1.png);
  line-height:53px;
  width: 53px;
  height: 52px;
}
.cluster-2{
  background-image:url(images/m2.png);
  line-height:53px;
  width: 56px;
  height: 55px;
}
.cluster-3{
  background-image:url(images/m3.png);
  line-height:66px;
  width: 66px;
  height: 65px;
}