<div class="hit-the-floor">404</div>

.hit-the-floor {
  color: #fff;
  font-size: 12em;
  font-weight: bold;
  font-family: Helvetica;
  text-shadow: 
    0 1px 0 #ccc, 
    0 2px 0 #c9c9c9, 
    0 3px 0 #bbb, 
    0 4px 0 #b9b9b9, 
    0 5px 0 #aaa, 
    0 6px 1px rgba(0,0,0,.1), 
    0 0 5px rgba(0,0,0,.1), 
    0 1px 3px rgba(0,0,0,.3), 
    0 3px 5px rgba(0,0,0,.2), 
    0 5px 10px rgba(0,0,0,.25), 
    0 10px 10px rgba(0,0,0,.2), 
    0 20px 20px rgba(0,0,0,.15);
}

.hit-the-floor {
  text-align: center;
}

body {
  background-color: #f1f1f1;
}

// Silence is Golden