You can move a unit to a position immediately above or below another unit. You can also move a unit so that its top edge is aligned with that of the unit in the left or right column.
in the lower right.
* When the top edge of the unit you are moving is aligned with that of the unit on the left or right, a blue horizontal line appears. When you stop dragging while this line is displayed, the top edges of these units are aligned with each other.

Between units whose top edges are aligned with each other,
is displayed.
.