body{
   background-color:grey; 
   
}	

#wrapper {
    width: 960px;
    margin-right: auto;
	margin-left: auto;
    
}	

#impressum {
    color: #4b4b4b;    	
}	

header {
  
	
}	

nav {
    text-align: center;
    height: 50px;	
}	
  
nav ul {
    list-style-type: none;
}	
  
nav li{
    display: inline;
    margin-right: 20px; 
     
}

a{
    
	
}	
 
  
section {
    width: 650px;
    height: 550;
    float: right;
    margin-bottom: 20px; 
    
	
}	

aside {
    width:310px;
    height:550;
	float: left;
    margin-bottom: 20px;
    
	
}	

footer {
   height: 25px;
   clear: both;

}	

button {
    background-color: aqua;
    color: red;
    text-align: center;
    width: 100px;
    
}

tr {
    background-color: white;
    text-align: center;
    color: black;

}