<div class="container">
  <div class="block block-1"></div>
  <div class="block block-2"></div>
  <div class="block block-3"></div>
</div>


body {
  background-color: black;
}

.block {
  width: 100%;
  height: 100px;
  background-color: white;
}

.block-1 {
  z-index: 3;
}

.block-2 {
  z-index: 2;
}

.block-3 {
  z-index: 1;
}