as per this question Browsers' default CSS stylesheets
add *{margin:0; padding:0;} which will remove default margin and padding given by browsers
or you can also use reset.css
* {
margin: 0;
padding: 0;
}
body {
margin: 0;
padding: 0;
background-color: #ffffcc;
}
#content {
width: 900px;
margin-left: auto;
margin-right: auto;
border: 0;
background-color: #ccccff;
}