RewriteEngine On
RewriteCond %{REQUEST_FILENAME}.php -f
RewriteRule ^([a-zA-Z0-9_-]+)$ $1.php [L]
DirectoryIndex index.php

# Only rewrite if not root
RewriteCond %{REQUEST_URI} !^/JSC/?$
RewriteCond %{REQUEST_FILENAME}.php -f
RewriteRule ^([a-zA-Z0-9_-]+)$ $1.php [L]