.ring {
  --l: 5;
  width: 30vmin;
  aspect-ratio: 1;
  border-radius: 100vmax;
  border: 0.5vmin double color-mix(in lab, currentcolor 40%, #0000);
  position: relative;
}

.dot {
  --del: 8s;
  --clr: hsl(calc(var(--i) * 360deg / var(--t) ) 75% calc(var(--l) * 6% + 15%));
  position: absolute;
  background-color: var(--clr);
  border: 1px solid;
  border-radius: 100vmax;
  width: 4vmin;
  aspect-ratio: 1;
  offset-path: border-box;
  animation: followpath var(--del) ease-out infinite calc((var(--del) / (-1 * var(--t))) * var(--i));
}

@keyframes followpath {
  100% {
    offset-distance: 100%;
  }
}
body {
  min-height: 100vh;
  margin: 0;
  display: grid;
  place-content: center;
  color: #1f2020;
  background-color: #F9F6EF;
  background-image: radial-gradient(circle, #F9F6EF, #EBEBE3), radial-gradient(at 100% 20%, #5EB0E525, #0000 70%), radial-gradient(at 20% 20%, #F3D06025, #0000 70%), radial-gradient(at 20% 100%, #A5282C25, #0000 70%), radial-gradient(at 100% 100%, #AEE1CD25, #0000 70%);
  background-blend-mode: darken;
}