A seating arrangement includes a base, a lower shell having a portion fixedly coupled to the base, and an upper shell supported entirely by the lower shell, the upper shell comprising a seating portion, a backrest portion moveable between an upright position and a reclined position, and a curved transition portion extending between the seating portion and the backrest portion, wherein a pair of laterally spaced longitudinal slots are located in portions of the seating portion and the transition portion thereby defining a central region and laterally spaced side regions, wherein the central region moves up relative to the side regions during recline.