body{padding:0;margin:0;}
.header{text-align:center;}
.footer{text-align:center;background:black;color:white;padding-top:10px;}
nav {	
	background-color:black;
	text-align:center;
	max-width:100%;
	padding: 5px;
}

nav a, nav span {
    display: inline-block;
    width: 10em; 	/* Breite den in li enthaltenen Elementen zuweisen */
	margin:5px;
    padding: 2px;
    text-decoration: none; 
    font-weight: bold;
    border: 1px solid grey;
    border-radius: 10px 10px 10px 10px;
    box-shadow: 0px 0px 8px white inset;
    color: white; 
    background:Blue;
    -webkit-transition: all 0.3s;
    transition: all 0.3s;
  }
			
nav a:focus, nav a:hover, nav span {                       /* aktuelle Unterseite kennzeichnen */
	color: black; 
	background-color: LightSteelBlue ;
}