body {
    overflow: hidden;
    background: #808080;
}

span {
    position: absolute;
    border-radius: 50%;
    transform: translate(-50%, -50%);
    box-shadow: inset 0 -4px 8px rgba(0,0,0,.2);
    transition: .1s;
}

.poped {
    box-shadow: inset 0 0 6px #f7f9ef;
}