button.loading {
  position: relative;
  background: #fff !important;
  color: #fff !important;
  pointer-events: none;
}

button.loading > * {
  visibility: hidden;
}

button.loading::after {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  width: 20px;
  height: 20px;
  margin: -10px 0 0 -10px;
  border: 2px solid purple;
  border-top-color: transparent;
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

button.loading::before {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  width: 14px;
  height: 14px;
  margin: -7px 0 0 -7px;
  border: 2px solid mediumorchid;
  border-bottom-color: transparent;
  border-radius: 50%;
  animation: spinReverse 1s linear infinite;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

@keyframes spinReverse {
  0% { transform: rotate(360deg); }
  100% { transform: rotate(0deg); }
}