RewriteEngine on
  RewriteRule ^products/([^/\.]+)/([^/\.]+)/([^/\.]+)/?$ product.php?name=$3&category=$1 [L]
  
  # URLs ending in slash: domain.com/products/1/2/3/
  #RewriteCond %{REQUEST_URI}  !^products/([^/\.]+)/([^/\.]+)/([^/\.]+)$
  #RewriteRule ^products/([^/\.]+)/([^/\.]+)/([^/\.]+)/(.+)\.(js|css|gif|jpe?g|png)$ $3/$4.$5 [L] # for no slash

  # URLs not ending in slash: domain.com/products/1/2/3  
  RewriteCond %{REQUEST_URI}  !^products/([^/\.]+)/([^/\.]+)/([^/\.]+)$
  RewriteRule ^products/([^/\.]+)/([^/\.]+)/([^/\.]+)/(.+)/([^/\.]+)\.(js|css|gif|jpe?g|png)$ $4/$5.$6 [L]