 <style>
.is-invalid {
  border-color: #dc3545;
}

.invalid-feedback {
  display: block;
}
.is-invalid {
  border: 1px solid #dc3545 !important;
}
.invalid-feedback {
  font-size: 12px;
  color: #dc3545;
  margin-top: 4px;
}
</style>