Toggleable Accordion

Hey there,

I'm trying to make an accordion that will allow me to open one or more sections, and also close all of them back up. I've gotten as far as having them both start closed, allowing multiple sections open, but when I try to close them both, they become mutually exclusive.

Here's the fiddle:

http://ift.tt/1vkMrMb

Thanks in advance.

Toggleable Accordion