Deneyiniz bunu hocam
RewriteEngine on

RewriteCond %{HTTP_HOST} ^localhost/ [NC]
RewriteRule ^(.*)$ http://localhost/$1 [L,R=301,NC]

RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME}.php -f
RewriteRule ^(.*)$ $1.php

RewriteCond %{REQUEST_URI} !^/detay.php
RewriteRule ^([^/_.]+)$ detay.php?url=$1 [L,QSA]

RewriteRule ^sayfa/([^/_.]+)$ index.php?page=$1 [L,QSA]

# 404 hata sayfası yönlendirme kodu
ErrorDocument 404 http://localhost/
<IfModule mod_security.c>
SecFilterEngine Off
SecFilterScanPOST On
</IfModule>