The testing attribute for /Configuration controls whether styles are included on each page or exported to external stylesheets that are linked to each page.

If testing is true, styles are embedded on each page. Some browsers are slow to recognize that linked stylesheets have changed, which makes debugging stylesheets tedious and tricky.

If testing is false, styles are exported as separate files in the /css directory, and the appropriate files are linked to each page. This is best for deployment, since pages will load more quickly and consume less bandwidth.