I was working on a card, clicked close because it was not obvious that it wouldn't save. I thought closing the card just meant closing and save. I was surprised to learn that it completely deleted my draft without so much as asking me to confirm that this is what I wanted to do. Auto saved drafts should be standard, and if you do have a non-clear button for discarding, maybe a popup to confirm would be a good idea? just lost 45 minutes of work because of this, very frustrating.