.parent {

  position:  relative;

  width: 750px;

  height: 7150px;

  background: red;

  border: solid 1px #000;

  z-index: 1;

}

.child {

  position: absolute;

  background-color: blue;

  z-index: 0;

  color: white;

  top: 0;

}

.wrapper

{

  position: relative;

  background: green;

  z-index: 10;

}