.centerContainer {
    position: relative;
    width: 100%;
    height: 100%;
}

.centerItem {
    position: absolute;
    top: 50%;
    left: 50%;
    -ms-transform: translate(-50%, -50%);
    transform: translate(-50%, -50%);
}

.m20 {
    margin: 20px;
}

.ml20 {
    margin-left: 20px;
}

.mr20 {
    margin-right: 20px;
}

.ptr { cursor: pointer; }