DirectoryIndex index.php index.html
Options -Indexes
Options -MultiViews

RewriteEngine On

# 0) Serve existing files/directories as-is
RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ - [L]

# 1) Internal map: /page or /page/ -> /page.php (if such PHP file exists)
RewriteCond %{REQUEST_FILENAME}.php -f
RewriteRule ^(.+?)/?$ $1.php [L]

# 2) Optional: strip trailing slash for non-directories (keeps .php links working)
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.+)/$ $1 [R=301,L]

<FilesMatch "\.(js)$">
  FileETag None
  <IfModule mod_headers.c>
    Header unset ETag
    Header set Cache-Control "max-age=0, no-cache, no-store, must-revalidate"
    Header set Pragma "no-cache"
    Header set Expires "Wed, 11 Jan 1984 05:00:00 GMT"
  </IfModule>
</FilesMatch>