.parent {
  position: relative;
  width: 80%;
  height: 80vh;
  margin: 5% auto;  
  background: #fff;
  box-shadow: 0px 0px 5px #000;
}
.child{
  position: absolute;
  top:-5%;
  bottom:-5%;
  right: 10%;
  width: 30%;
  background: #fff;
  box-shadow: 0px 0px 5px #000;
}