Div overlap with opaque background

by jost_s

HTML

<div>
AB
</div>
<div class="overlapping">
CD
</div>

CSS

div {
  background-color: lightblue;
  width: 100px;
  height: 100px;
  font-size: 3rem;
  display: flex;
  align-items: center;
  justify-content: center;
}

.overlapping {
  margin-left: 50px;
  margin-top: -50px;
  border: 1px solid white;
}