.marker-cluster {
    background-clip: padding-box;
    border-radius: 20px;
    background-color: rgba(50, 94, 106, 0.8);
}

.marker-cluster div {
    width: 30px;
    height: 30px;
    margin-left: 5px;
    margin-top: 5px;
    text-align: center;
    border-radius: 15px;
    font: 12px "Helvetica Neue", Arial, Helvetica, sans-serif;
    background-color: rgba(50, 94, 106, 0.8);
}

.marker-cluster span {
    line-height: 30px;
    color:white;
}