.spinner {
  display: none;
  position: fixed;
  top: 50%;
  left: 50%;
  width: 48px;
  height: 48px;
  margin: -24px 0 0 -24px;
  border: 5px solid #232526;
  border-top: 5px solid var(--accent);
  border-radius: 50%;
  animation: spin 1s linear infinite;
  z-index: 1000;
}
.spinner.active {
  display: block;
}
@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}