.ng-valid[required], .ng-valid.required  {
  border-left: 5px solid #42A948; /* green */
}

.ng-invalid:not(form)  {
  border-left: 5px solid #a94442; /* red */
}

.loading {
  border-bottom: 6px solid rgba(0, 0, 0, .1);
  border-left: 6px solid rgba(0, 0, 0, .1);
  border-right: 6px solid rgba(0, 0, 0, .1);
  border-top: 6px solid rgba(0, 0, 0, .4);
  border-radius: 100%;
  height: 25px;
  width: 25px;
  animation: rot .6s infinite linear;
}
@keyframes rot {
  from {transform: rotate(0deg);}
  to {transform: rotate(359deg);}
}