How to unselect/decrease a resource from a trade in the trade window.
Got the game recently on mobile and PC and immediately ran into the problem of now knowing how to remove/unselect a resource from a trade. I would accidentally add a wood or something to the trade and not know how to undo that action. Couldn't figure it out on mobile or PC but I know it's possible.
Up or down on the card in the trade. So if you click the top part of the card, it add, bottom it takes away.