When taking items from a container, it is possible to take either one, half or all of them. Currently, these options are unavailable when moving items to a container. E.g. You have two items, each having a weight of 3 (= total of 6 weight). The container you're trying to move these items to only has place for 5 more weight. At this point, you cannot drag them into the container because that would move all of them (6 weight) and the container only has room for 5. You would still like to move at least one of these into the container, but this is currently impossible. My suggestion is to add options for moving single, half, all and perhaps even an x amount of items into a container.