Demo: CSS offset-anchor

<div class='container'>
  <div class='box'>
    Move Me!
  </div>
</div>

.container {
  width: 100vw;
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  background-color: #f0f0f0;
}

.box {
  width: 100px;
  height: 100px;
  background-color: #3498db;
  color: white;
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: 16px;
  animation: move 2s infinite alternate;
  offset-anchor: 50% 50%;
}

@keyframes move {
  0% {
    transform: translate(0, 0);
  }
  100% {
    transform: translate(200px, 200px);
  }
}

// No JavaScript required for this demo