SortableJS/Sortable ? reverse-engineered prompt

I'd like to create a JavaScript library that makes HTML lists reorderable using drag and drop. It needs to be lightweight and work on its own, without needing jQuery or any big framework like React or Angular.

The main thing is that a user should be able to drag an item to reorder it within the same list, or even drag an item from one list and drop it into a different one. It should feel really polished, with smooth animations as the items move around. It also needs to be mobile-friendly and work well on touch devices. If a list is really long, the page should automatically scroll when the user drags an item toward the top or bottom. As a bonus, it would be awesome if you could select and drag multiple items at once.