Abstract: A mobile phone may include a housing defining at least a portion of a back exterior surface of the mobile phone, a display stack at least partially within the housing, the display stack defining an active region configured to produce a graphical output, and a transparent cover positioned over the display stack. The transparent cover may define a first portion covering the active region of the display stack, a second portion adjacent the first portion, and a hole in the second portion and extending through the transparent cover. The mobile phone may also include a button element positioned in the hole of the transparent cover, a force-sensing system configured to detect an input applied to the button element, a circuit board coupled to the force-sensing system, and a shim positioned below the first portion of the transparent cover and having same thickness that as the circuit board.