a.tooltip{
  position:relative; 
  font-size:18px; 
  color:#039;
  text-decoration:none;
  cursor:help; 
  text-align:left;
  }

  a.tooltip:hover{
  background:transparent;
  color:#f00;
  z-index:25; 

  }
  a.tooltip span{display: none
  }

  a.tooltip:hover span{ 
  display:block;
  position:absolute;
  width:410px; 
  top:20px;
  left:0;
  font-size: 14px;
  padding:5px;
  border:1px solid #999;
  background:#383838; 
  z-index: 100; 
  color: white;
// mais claro  box-shadow:5px 5px 10px #ccc;
  box-shadow: 5px 5px 10px #333, -5px -5px 10px #ccc;
  }