body {background-color:#efefef;
    font-family:arial, verdana, sans-serif;
    text-align:center;}
  
  .page {
    margin-left:auto;
    margin-right:auto;
    text-align:left;
    width:700px;
    font-size:12px;
    background-image:url(basic-web-html-09-images-2columnbackground.gif);
    background-repeat:repeat-y;
    border:1px solid #666666;}
  
  .header {
    padding:3px;
    background-color:#ffffff;}
  
  .nav {
    font-weight:bold; 
    padding:5px; 
    float:left; 
    width:100px;}
  
  .content {
    padding:10px;
    margin-left:100px;}