offset-distance

offset-distance: 0%;

offset-distance: 80%;

offset-distance: 50px;

<section class="default-example" id="default-example">
  <div class="transition-all" id="example-element"></div>
</section>

#example-element {
  width: 24px;
  height: 24px;
  background: #2bc4a2;
  offset-path: path("M-70,-40 C-70,70 70,70 70,-40");
  clip-path: polygon(0% 0%, 70% 0%, 100% 50%, 70% 100%, 0% 100%, 30% 50%);
}
/* Provides a reference image of what path the element is following */
#default-example {
  background-position: calc(50% - 12px) calc(50% + 14px);
  background-repeat: no-repeat;
  background-image: url('data:image/svg+xml;utf8,<svg xmlns="https://www.w3.org/2000/svg" viewBox="-75 -45 150 140" width="150" height="140"><path d="M-70,-40 C-70,70 70,70 70,-40" fill="none" stroke="lightgrey" stroke-width="2" stroke-dasharray="4.5"/></svg>');
}

/* 既定値 */
offset-distance: 0;
/* offset-path の途中 */
offset-distance: 50%;
/* パス上の固定距離の位置 */
offset-distance: 40px;
/* グローバル値 */
offset-distance: inherit;
offset-distance: initial;
offset-distance: revert;
offset-distance: revert-layer;
offset-distance: unset;

<div id="motion-demo"></div>

#motion-demo {
  offset-path: path("M20,20 C20,100 200,0 200,100");
  animation: move 3000ms infinite alternate ease-in-out;
  width: 40px;
  height: 40px;
  background: cyan;
}
@keyframes move {
  0% {
    offset-distance: 0%;
  }
  100% {
    offset-distance: 100%;
  }
}