Generador de cargadores CSS

<div class="loader-spinner"></div>

.loader-spinner {
  width: 40px;
  height: 40px;
  border: 5px solid rgba(0, 0, 0, 0.1);
  border-left-color: #3B82F6;
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}