The code is as following:
file:index.php
<?php include("fix.php");?>
file: fix.php
<html> <head> <title></title> <link rel="stylesheet" type="text/css" href="styles/styles.css" /> </head> <body style="margin:0px;"> <h1 style="background-color:red;margin:0px;">Problem</h1> </body></html>
When I open file fix.php in firefox and chrome are ok (there is no margin between tag h1 and top boundary of browsers).
However, when I open file index.php, in firefox is OK (no margin), but in Chrome, there a margin between them