.button {
    position: absolute;
    background-size: 0px 0px;
    background-repeat: no-repeat;
    transition: all linear 200ms;
    border-radius: 2px;
    pointer-events: auto;
    cursor: default;
    overflow: hidden;
}
#buttonLabel {
    position: absolute;
    left: 3px;
    top: 3px;
    right: 3px;
    bottom: 3px;
    pointer-events: none;
    text-align:center;
}