According to one general aspect of the invention, an input device includes a collapsible structure and a sheet of material. The sheet of material is disposed above the collapsible structure and includes an attached edge that is affixed to a housing of the input device, creating a pivot point. The sheet of material also includes a front edge opposite the attached edge, a left edge, and a right edge. The sheet of material has a width extending from the left edge to the right edge and a height extending from the front edge to the pivot point. A first opening is formed proximate the front edge of the sheet of material. The collapsible structure is disposed below a portion of the sheet of material located between the front edge and a midpoint of the height of the sheet. The collapsible structure is approximately centered between the left and right edges.