fieldset.btn-boxes{
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
}

fieldset.btn-boxes input[type="checkbox"]{
    border: 1px solid #ced4da;
    border-radius: .25rem 0 0 .25rem;
    padding: .5em;
    position: relative;
    display: none;
}