This is the first item's accordion body. It is hidden by default,
        until the collapse plugin adds the appropriate classes that we use to style each
        element. These classes control the overall appearance, as well as the showing and
        hiding via CSS transitions. You can modify any of this with custom CSS or
        overriding our default variables. It's also worth noting that just about any HTML
        can go within the .accordion-body, though the transition does
        limit overflow.