<div class="spinner">
  <!-- icon from https://heroicons.com/ -->
  <svg xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" stroke="currentColor">
  <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M4 4v5h.582m15.356 2A8.001 8.001 0 004.582 9m0 0H9m11 11v-5h-.581m0 0a8.003 8.003 0 01-15.357-2m15.357 2H15" />
</svg>
</div>

.spinner {
  width: 48px;
  height: 48px;
  animation: rotateMe 2s linear infinite;
}

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