@keyframes spin {
  0% { rotate: 0; }
  100% { rotate: 360deg;}
}

:root {
  background: #777;

  &::before {
    content: "";
    width: 50vmin;
    aspect-ratio: 1;
    border-radius: 50%;
    position: absolute;
    top: 50%;
    left: 50%;
    translate: -50% -50%;
    background:
      radial-gradient(farthest-side, #000 2%, #fff 0 3.5%, red 0 20%, #0000 0 80%, lime 0),
      repeating-conic-gradient(#0000 0 60deg, red 0 120deg),
      lime;
    animation: spin 3s linear infinite;
  }
}