div#boxmodel_sample {  
  margin: 20px auto 0 auto;
  width: 330px;
  text-align: left;
}
ul {  
  margin: 0;
  padding: 10px 0 ;
  background: #fc9 ;
}
ul li.list1 {  
  margin: 10px auto;
  padding: 10px;
  width: 200px;
  background: #ff9;
}
ul li.list2 {  
  margin: 10px 20px;
  padding: 10px;
  width: 200px;
  background: #ff9;
  border: 2px dotted #099;
}