<div class="wrapper">
<div class="inheritance_demo box">
  Inheritance with em units demo
</div>
</div>

.box {
  background: #3498db;
  color: #fff;
}

.wrapper {
  font-size: 1.25em;
}

.inheritance_demo {
  font-size: 14px;
  padding: 1.5em;
}