t {
  background: red;
  width: 100px;
  height: 100px;
}

html::view-transition-group(target) {
  animation-play-state: paused;
}

html::view-transition-new(target) {
  animation: unset;
  opacity: 0;
}

html::view-transition-old(target) {
  animation: unset;
  opacity: 1;
}

html::view-transition-group(root) {
  display: none;
}

html::view-transition { background: lightpink; }
</style>

<div id="target"></div>

<script>
failIfNot(document.startViewTransition, "Missing document.startViewTransition");

fun