Code is quite easy :
<html xmlns="http://www.w3.org/1999/xhtml">
<body style="padding:0; margin:0;">
<form method="post" action="/default.aspx" id="form1" style="margin: 0px; padding: 0px;">
<div id="container-main" style="background-color:Red; height:1825px; position:relative;"> </div>
<div id="fascia-chiusura" style="background-color:#5CAE22; height:11px; position:relative; width:100%;"> </div>
</form>
</body>
</html>
But on Firefox/Chrome it gets a strange “space” at the bottom, which is not in the HTML element. Why this behaviour? And how can I fix it?
Screenshot :

http://jsfiddle.net/rtVPb/4/
Remove the
in your last div and it works fine. The space from the is larger than the 11px defined in the div so it creates an overflow and you get a white part.You can check this behaviour here where I added some visible text..