.cluster > div {

    top: 0 !important;
    left: 0 !important;
    height: 100% !important;
    display: flex;
    align-items: center;
    justify-content: center;
    line-height: 1 !important;
}

.cluster > div > span {

    display: block;
    line-height: 1 !important;
}