相关疑难解决方法(0)

.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;
}

<div class="wrapper">
  <div class="parent">
    parent parent
    <div class="child">
      child child child
    </div>
  </div>
</div>