.input-group-addon {
    padding: .375rem .75rem;
    margin-bottom: 0;
    font-size: 1rem;
    font-weight: 400;
    line-height: 1.25;
    color: #495057;
    text-align: center;
    background-color: #e9ecef;
    border: 1px solid rgba(0,0,0,.15);
    border-radius: .35rem;
    border-top-left-radius: 0;
    border-bottom-left-radius: 0;
}