In order to properly format printed reports for maximum layout and style flexibility, it would be ideal for Gnucash to:

1) Generate html code with classes for all elements such as tables and divs. Also enclose all text data with the <span> tag.

2) Allow users to set the path to a local 'custom.css' file, which would then be declared in the report as:

<link rel="stylesheet" type="text/css" href="/home/user/gnucash/css/custom.css">

3) Allow Gnucash to output the pdf file using the html report as input.

This would go a long way for users that need more than the basic printouts produced by the program.