html {
	        height:100%;
	        width:100%;
	    }
	    body{
	        background:#D9E2E8 url('https://ckmsystem.com/fondo_ckm.jpg') no-repeat center center fixed;
			-webkit-background-size: cover;
			  -moz-background-size: cover;
			  -o-background-size: cover;
			  background-size: cover;
	
	    }