Demo: CSS offset-rotate

<div class='container'><div class='box'></div></div>

.container { width: 200px; height: 200px; position: relative; overflow: hidden; }

.box {
  width: 50px;
  height: 50px;
  background-color: #3498db;
  position: absolute;
  animation: move 4s infinite;
  offset-path: path('M 0 0 Q 100 200 200 0');
  offset-rotate: auto;
}

@keyframes move {
  0% { offset-distance: 0%; }
  100% { offset-distance: 100%; }
}

// No JavaScript required for this demo