.ban {
	padding: 0;
	padding-top: 100px;
	margin: 0;
    list-style: none;
    height: 420px;
    /* background: url(../imagenes/bg_1.jpg) no-repeat fixed center; */
    z-index: -100;
    
}
body {
	margin: 0;
	padding: 0;
	position: relative;
	background: url(../imagenes/bg_1.jpg) no-repeat fixed center top;
}