a.wp-socialicon-media-icon {
    background-position: 0 0;
    display: inline-block;
    height: 32px;
    margin-right: 6px;
    overflow: hidden;
    text-indent: -1000px;
    transition: background-position 0.25s ease 0s;
    width: 32px;
}
a.wp-socialicon-media-icon:hover {
    background-position: 0 -32px;
}