#loader {
  width: 100vw;
  height: 100vh;
  position: absolute;
  top: 0;
  left: 0;
  background: rgba(0, 0, 0, 0.5);
  z-index: 9999;
}

.loader {
  position: absolute;
  left: 50%;
  top: 50%;
  /* transform: translate(-50%, -50%); */
}

/* HTML: <div class="loader"></div> */
.loader {
  width: 50px;
  aspect-ratio: 1;
  --_c: no-repeat radial-gradient(farthest-side, black 92%, #0000);
  background: var(--_c) top, var(--_c) left, var(--_c) right, var(--_c) bottom;
  background-size: 12px 12px;
  animation: l7 1s infinite;
}
@keyframes l7 {
  to {
    transform: rotate(0.5turn);
  }
}