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

.spinner {
  width: 40px;
  height: 40px;
  border: 4px solid #e1e5e9;
  border-top: 4px solid #007bff;
  border-radius: 50%;
  margin: 20px auto;
  animation: spin 1s linear infinite;
}