An electronic device such as a portable computer may have a housing with a rectangular recess in which layers of display structures such as a light guide panel layer and other light guide structures are directly mounted without intervening chassis members. Mating alignment features in the housing and display structures may be used to align the display structures relative to the housing. A display may be formed from glass layers such as a color filter glass layer and a thin-film transistor glass layer. Backlight for the display may be generated by an array of light-emitting diodes. The light guide panel may direct light from the light-emitting diodes through the glass layers. A clamp may be used to hold the light-emitting diodes and light guide structures in place in the recess. An undercut in the housing may also hold the light guide structures in place.