.input-group-append .btn {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0.375rem 0.75rem;
  border-top-right-radius: 0.25rem;
  border-bottom-right-radius: 0.25rem;
}

.input-group-append .btn i {
  font-size: 1rem;
}