Image Galleries don't work in Safari

I just published my first Sparkle-built website, but there is a problem. The image galleries work in all browsers, except for

As you might imagine, a glaring issue like this would have been brought up by other Sparkle users and would be fixed. So there must be something with your setup. Please provide a link to a published website showing the problem, or send us the project at feedback@sparkleapp.com and we’ll take a look.