The overlay window became all greyed
From what I can tell, css from your drupal site is majorly interfering with CiviCRM. Specifically, the interference is targeting jQuery UI, probably because you have a copy of jQuery UI loading via Drupal. Try:


Disabling the jQuery UI module (or find a way to disable it just for CiviCRM pages)
Choosing a simpler theme for CiviCRM pages, particularly one that does not bundle a copy of jQuery UI.