/* full-screen semi-opaque backdrop */
#app-spinner {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(255, 255, 255, 0.8);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 9999;
}

/* simple CSS spinner */
.spinner {
  border: 6px solid #e0e0e0;
  border-top: 6px solid #3498db;
  border-radius: 50%;
  width: 60px;
  height: 60px;
  animation: spin 0.8s linear infinite;
}

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