<!DOCTYPE html>
Passes if there is a brown square.
<div id="target"
     style="overflow: hidden; width: 100px; height: 100px;
            background: linear-gradient(to bottom right, green, red);
            background-attachment: local">
  <div style="width: 3000px; height: 3000px"></div>
</div>
<script>
target.scrollTop = 1500;
target.scrollLeft = 1500;
</script>