<!DOCTYPE html>
<meta charset="utf-8">
<title>compute the kind of widget: animation origin only</title>
<link rel="match" href="appearance-animation-002-ref.html">
<style>
  .bg200 {
    animation: 1e10s steps(2, start) animate-bg;
  }
  @keyframes animate-bg {
    to {
      background-color: rgb(255, 0, 0);
    }
  }
</style>
<input value="text" id=input>
<script>
  document.documentElement.offsetTop;
  input.classList.toggle('bg200');
</script>
<p>PASS if the input field does not have a red background</p