.input-group-prepend,
.input-group-prepend span{
    min-width: 100px;
}

input[type=color]{
    width: 38px;
    height: 38px;
    cursor: pointer;
}
.ml--1{
    margin-left: -1px;
}

.input-group>.input-group-prepend:not(:first-child)>.input-group-text{
    border-top-left-radius: 0.25rem;
    border-bottom-left-radius:  0.25rem;
}

#qrcode{
    width: 256px;
    height: 256px;
}