body {
margin: 0;
padding: 0;
background-color: black;
}

#wrapper {
width: 850px;
margin: 0 auto;
padding: 0;
}

header#oben {
margin: 20px 0 0 20px;
padding: 10px;
border: 5px solid #ccc;
background-color: #e55;
height: 100px;
width: 800px;
}

nav#menu {
margin: 20px;
padding: 10px;
border: 5px solid #ccc;
background-color: #55F;
width: 200px;
float: left;
}

section.content {
margin: 20px 0 20px 0;
padding: 10px;
border: 5px solid #ccc;
background-color: #5F5;
width: 550px;
float: left;
}

footer#unten {
margin: 20px 20px 0 20px;
padding: 10px;
border: 5px solid #ccc;
background-color: #ee5;
height: 100px;
width: 800px;
clear: both;
}