Drop-downs on "Customize" admin page don't open

When I click the Customize link on the admin page to edit Customizr settings, the drop-down options don’t open anymore. Also, is there a file that the “Advanced Options” custom CSS is saved? I want to pull it from there and add it to what I’ve done in my child theme’s style.css, but since these drop-downs don’t open, I can’t get to what I’ve done already.