span.doiBadge {
    font-family: 'Helvetica Neue',Helvetica,Arial,sans-serif;
    color: #fff;
    background: #000;
    text-decoration: none;
    padding: 2px 0 2px 4px;
    border-color: #000;
}

span.doiBadge a {
    color: #fff;
    background: #09c;
    text-decoration: none;
    margin-left: 4px;
    padding: 2px 5px 2px 4px;
    border-radius: 0 5px 5px 0;
}