We will animate the size of a named collapsible whenever it's status changes. So don't change the visiblity of the collapsible container with CSS, but rather its children.
I can be hidden. Or not.
Group
We will only allow one collapsible of group to be open (and auto-close all others). This will behave like an accordion.
I am the content number ##(i}
I am the content number ##(i}
I am the content number ##(i}
API
It is very simple to open/close a collapsible via custom JS. Just change the data-hidden attribute and we take care of the rest.