<!DOCTYPE html>
<head>
<style>
.composited {
  /* Not using will-change:transform because it ignores subpixel accumulation. */ 
  will-change: opacity;
}

.box {
  width: 100px;
  height: 100.5px;
}

.behind {
  position: absolute;
  z-index: 1;
  top: 100px;
  left: 100px;
  background-color: blue;
}

.middle {
  position: absolute;
  z-index: 1;
  top: 15px;
  left: 15px;
  background-color: lime;
}

.middle2 {
  position: absolute;
  z-index: 1;
  top: 130.5px;
  left: 60px;
  background-color: magenta;
}

.top {
  position: absolute;
  z-index: 1;
  top: 70.5px;
  left: 120px;
  background-color: cyan;
}

.container {
  position: absolute;
  z-index: 1;
  top: 25.5px;
  left: 25px;
  width: 300px;
  height: 300px;
  background-color: gray;
}

div:hover {
  background-color: green;
}

</style>
</head>
<body>
  <div class="container">
    <div class="composited box behind"></div>
    <div class="box middle"></div>
  </div>
<div class="box middle2"></div>
<div class="box top"></div>
</body>