JSFiddle - React, Tailwind, and code Playground

HTML

<div class="parent"><input /><div class="child"><div class="subChild"><input /></div></div></div>

CSS

html,body{
  
  overflow:hidden;
  height: 100%;
  width: 100%;
}
.parent {
  pointer-events:none;        
  position: absolute;
  z-index:10;
  top:0px;
  left:0;
  right:0;
  bottom:0px;
  background-color:#ff0000;
  height: auto;
  overflow-y:auto;
}
.child {
    pointer-events:auto;
    position: absolute;
    z-index:11;
    top:50px;
    left:0;
    right:0;
    bottom: 0;
    max-height: 100%;
    background-color:#0000FF;
}
.subChild{
    height: 500px;
    background-color:yellow;
    width: 100%;
  }
}