I am using a WAMP server and I need to change the \"404 not found page\" style using CSS. How can I do it?
You can redirect 404 error pages using .htaccess file to your custom pages.
Design your custom 404 page with using HTML/CSS. Once you have your 404 page setup, all you need to do is send visitors to incorrect url’s to this page. To do this just add the following line to your .htaccess file:
ErrorDocument 404 /404.php
You can place the 404 error template anywhere you want. For example you could place all error messages in a folder called errormessages
ErrorDocument 404 /errormessages/404.php
See this article, How to redirect your 404 error to a custom page