#loading-screen {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-55px, -55px);
    z-index: 10;
}
#loading-screen div {
  width: 100px;
  padding: 10px;
  aspect-ratio: 1;
  border-radius: 50%;
  background: #999;
  --_m: 
    conic-gradient(#0000 10%,#000),
    linear-gradient(#000 0 0) content-box;
  -webkit-mask: var(--_m);
          mask: var(--_m);
  -webkit-mask-composite: source-out;
          mask-composite: subtract;
  animation: l3 1s infinite linear;
}
@keyframes l3 {to{transform: rotate(1turn)}}