body {
  background-color: #CCCCCC;
  font-size: 12px;
  font-family: Verdana, Arial, Helvetica, SunSans-Regular, Sans-Serif;
  color:#FFFFFF;  
  padding:0px;
  margin:0px;
}
#content { 	
  position:absolute;
  height:200px; 
  width:400px;
  margin:-100px 0px 0px -200px;
  top: 50%; 
  left: 50%;
  text-align: left;
  padding: 0px;
  background-color: #EEEEEE;
  overflow: auto;
}
<div id="content">içerik</div>