<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html> <head> <style rel='stylesheet' type='text/css'> body { padding: 10px; margin: 10px auto; min-width: 500px; max-width: 900px; -moz-opacity: 0.7; } </style> </head> <body> this is a test. this is a test. </body> </html>