<style>
.non_intrusive {
  float: left;
  height: 50px;
  width: 80px;
  background-color: green;
}

.content_box_offset {
  margin-left: 80px;
  height: 50px;
  width: 30px;
  background-color: red;
}

.float_inside {
  float: right;
  width: 110px;
  height: 50px;
  background-color: green;
}
</style>
<!-- PASS if no red -->
<div>
  <div class=non_intrusive></div>
  <div class=content_box_offset><div class=float_inside></div></div>
</div>