site_new/stylesheets/layout.css
site_new/javascript/somescript.js
site_new/hallendetails.php
site_new/etc...

RewriteEngine on
RewriteBase /site_new/
RewriteRule ^(.*)/(.*).html$ hallendetails.php?id=$1&halle=$2 [L]

localhost/site_new/hallendetails.php?id=01&halle=Heimspielhalle_Gaissacher_Strasse

localhost/site_new/01/Heimspielhalle_Gaissacher_Strasse.html

/site_new/01/stylesheets/layout.css