Darstellungsfehler von Website

@charset "utf-8"; 
/* CSS Document */


body {
	width: 960px;
	height: auto;
	margin-left: auto;
	margin-right: auto;
	}
#site {
	width: 960px;
	height: auto;
	margin-left:auto;
	margin-right:auto;
	}

header {
	width: 100%;
	margin: 0;
	padding: 0;
	}

header ul {
	
	}
header li  {
	
	}
#logo {
	width:960px;
	height:70px;
	margin: auto;	}

nav {
	width: 960px;
	height: 70px;
	margin: auto auto 20px auto;
	display: table;
}

nav ul {
	display: table-row;
	}

nav li {
	display: table-cell;
	}

nav a {
	float: left;
	width: 190px;
	height: 60px;
	line-height: 60px;
	text-align: center;
	text-decoration: none;
	color: #333;
	border: 1px solid #CCC;
	border-radius: 15px;
	}