.error404{width: 740px;height: 400px;clear:both;overflow: hidden;margin: 100px auto 0;text-align: center;background: #f1f1f1 url('../img/under.jpg') no-repeat center top;}
.error404 p{vertical-align: middle;display: table-cell;width: 600px;height: 400px;font-size: 20px;}
.error404 p span{font-size: 30px;}