<!DOCTYPE html>
<style>
.fixed {
  position: fixed;
  background-color: #aef;
  width: 100px;
  height: 100px;
  top: 100px;
}
</style>
<div style="height: 1000px"></div>
<div class="fixed" style="left: 200px"></div>
<div class="fixed" style="left: 400px; will-change: transform"></div>
<script>
  scrollBy(0, 120);
</script>