Theme Horse

Hi almataina,
Just replace your code with this code. Hope this may help you

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /main/
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /main/index.php [L]
</IfModule>

# END WordPress

and i think you also have not changed all the database path too where for about page there must be http://almataina.com/main/about instead of http://almataina.com/about/

First of all check using the above .htaccess file.
Thank you!