Frage zu meinem Design

body {
background-image: url(http://s10.directupload.net/images/110215/hwh3fz6x.jpg);
background-repeat: repeat-x;
background-color: #252525;
font-family: Arial
font-size: 14px;
text-align: center;
}

a {
color: #000;
}

#content {
margin: 0 auto;
margin-top: -120px;
width: 800px;
float: right;
background-color: #ffffff;
font-family: Arial;
font-size: medium;
padding: 10px;}


#design1 {
width: 820px;
margin: 0 auto;
margin-top: 169px;
text-align: left;
background-color: #fff;
border: 1px solid #ffffbe;
}

#unten {
clear: both;
}

#header_container {
margin: 0 auto;
width: 640px;
height: 400px;
background-image: URL(http://img.webme.com/pic/g/gimp4you/splexlogo.png);
margin-top: -275px;
}

#nav_container {
margin: 0 auto;
margin-top: -190px;
list-style-type: none;
width: 820px;
height: 43px;
background-image: url(http://s13.directupload.net/images/110304/mj4rcdpy.png);
font-family: Arial;
text-align: center;
float: right;
padding-bottom:6px}


#nav_heading {
display: none;
}

#nav {
padding-left: 0px;
margin: 0;
}

#nav li {
list-style-type: none;
padding: 14px;
padding-left: 80px;
padding-right: 15px;
font-size: 1.1em;
display: block;
float: left;
color: #0A3C74;
}

#nav li.subpage {
display: none
}

#nav a {
color: #0A3C74;
text-decoration: none;
}

#nav a:hover {
color: #3F86D3;
text-decoration:none;
}

#below_content{
background-image:url(http://img.webme.com/pic/w/web-cube/footer1-1.png);
width:970px;
height:155px;
margin-left:auto;
margin-right:auto;
padding-left:30px;
padding-right:30px;}

.footer{
border:1px solid #d3d3d3;
background-color:#f1f1f1;}

.footer td:hover{
background-color:#9F85EB;}

.footer a{
color:#000000;}

.footer a:hover{
text-decoration:none;}

h1#header {display:none;}
h2#title {display:none;}
#sidebar_heading{display:none;}
#counter{display:none;}
#pre_header, #post_header, h1#header, #nav_heading {
display: none;
}

<div id="design1">

<div id="unten"></div></div>