#wrapper {
   width: 960px;
   margin-right: auto;
   margin-left: auto;
   height: 10px;
   font-size: 16px;
   font-family: arial, sans-serif
}

header {
   padding: 10px;
   height: 310px;
   width: 720px;
   text-align: center;
   }
nav{
   text-align: center;
   }
nav ul{
   list-style-type: none;
   text-align: center;
   }

nav li{
   display: inline;
   margin-right: 40px;
}

a {
   color: #777;
   text-decoration: none;
   font-family: arial, sans-serif
}
section {
   width: 960px;
   height: 300px;
   float: left;
}
footer {
   height: 50px;
   clear: boath;
   }