<script>
window.addEventListener('load', function() {
  document.getElementById('scroller1').scrollTop = 50;
  document.getElementById('scroller1').scrollLeft = 20;
  document.getElementById('scroller2').scrollTop = 50;
  document.getElementById('scroller2').scrollLeft = -25;
});
</script>

<div>You should see two green blocks below. No red or blue should be visible.</div>

<div class="group">
  <div id="scroller1" class="scroller" style="writing-mode: vertical-lr;">
    <div class="contents">
      <div cl