<style>
#d1 {
  position: absolute;
  top: 0px;
  left: 0px;
  will-change: transform;
  width: 64px;
  height: 64px;
  background: red;
}
#d2 {
  position: absolute;
  top: 0px;
  left: 0px;
  will-change: opacity;
  opacity: 0.5;
  width: 32px;
  height: 32px;
  background:blue;
}
#d3 {
  will-change: transform;
}
#d4 {
  will-change: transform;
}
</style>
<div id="d2">
  <div id="d3">
    sadf
  </div>
  <div id="d4">
    sdf
  </div>
</div>
<div id="d1">
</div>