@media only screen and (min-device-width: 320px) and (max-device-width: 767px) and (max-width: 767px) {

body {
	background: url(mantenimiento_mobil.jpg) no-repeat center center fixed;
	background-size: 100% 100%;
	margin: 0 auto;
	}
}

@media only screen and (min-width: 768px) {

body{
background: url(mantenimiento.jpg) no-repeat center center fixed;
background-size: 100% 100%;
margin: 0 auto;
}
}

/* Neutralidad */
html, body, header, nav, footer, p {
	margin:0;
	padding:0;
}

/* Etiquetas Estructurales */

header{
	width:100%;
	margin:0;
}

.div_rs {
	display:icon;
	padding:2em;
}

.img_rs{
	height:40px;
	width:40px;
}

li{
	display:inline;
}