Hi, this is my first topic here.

Why Firefox don't show the "margin-top" and "margin-bottom" of the first and
last elements of the code below?

The code:

XHTML

<!DOCTYPE ETC> .....
<body>
<div id="rap">
<h1 id="header">Header</h1>
<h1 id="content">Content</h1>
<h1 id="footer">Footer</h1>
</div>
</body>
....
CSS
* { margin:0; padding:0; }

body { background-color:#099; }

#rap { margin:10px auto; width:760px; background-color:black; }

h1 { margin:105px; width:750px; border:1px solid green; }

#header { background-color:red; }

#content { background-color:white; }

#footer { background-color:blue; }
Thanks from BraSil