Scrolling stack effect

gistfile1.css

/*
  
  Stack effect a la http://googleventures.com

  <div id="layer_base"></div>
  <div id="layer_one"></div>
 */

#layer_base {
  height: 100px;
  width :100%;
  position: static;
  top: 0;
  z-index: -2;
}

#layer_one {
  margin-top: 100px;
  position: relative;
  z-index: 2;

  /* box-shadow: 0 -5px 20px rgba(0, 0, 0, 0.2); */ /* fancy */
}