Menu overlaps with header, broke home page?

Hi all,
We use a combination of the usual menu from Sydney pro and a third party plugin (MetaSlider) for the header slider on our home page: www.bostonchoral.org. But the menu is hard to read on most pages, so I tried to add a background to it. Instead the menu broke entirely, and now we’re getting a homepage that looks like this. No idea what I did, and disabling all plugins did not fix it. Any idea what I did?

Hello there,

It appears to be normal now.

Have you been able to manage it yourself?

Regards,
Kharis