Stacking Context

by neoswf

HTML

<div id="div1">
     <div id="div2">
          absolute el, z-index:1000000000
    </div>
<div>

<div id="div3">
      <div id="div4">
        absolute el, z-index:1
      </div>
</div>

CSS

*{margin: 0;padding:0}
#div1{position:relative}
#div2{position:absolute;z-index:10000000;height:100px;background-color:blue;top:0;left:0;color:#fff}
#div3{position:relative}
#div4{position:absolute;z-index:1;height:30px;background-color:red;top:90px;left:90px;padding:10px}