如何将404页面重定向到自定义错误页面？

Question

Actually I am trying to redirect all the 404 page to 404.php using .htaccess

RewriteEngine on
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME}\.php -f
RewriteRule ^(.*)$ $1.php [NC,L]


RewriteCond %{HTTP_REFERER} !^http://(www\.)?localhost [NC]
RewriteCond %{HTTP_REFERER} !^http://(www\.)?localhost.*$ [NC]
RewriteRule \.(gif|jpg|css|js|png)$ - [F]

#for 404 page
Options +SymLinksIfOwnerMatch 
RewriteEngine On 
RewriteCond %{REQUEST_FILENAME} !-f 
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . 404.php [L]

my file structure is like structure

so what happens it works fine for the url like localhost/srmures/hr/fgh errorpageone

But when I change url like localhost/srmures/hr/fgh/gdj then it doesn't recognize the css file and add the html file into it.. errorpagetwo

So how to solve this?