Erics code implementation of TransitionGroup pt 3

styles.css

.circles {
    float: left;
    border-radius: 100%;
    width: 100px;
    height: 100px;
    background-color: yellow;
    position: absolute;
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
    margin: auto;
}


.box {
    width: 100px;
    height: 100px;
    background-color: #3498DB;
    position: absolute;
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
    margin: auto;
}