In an example embodiment of the present disclosure, an average distance in the first direction from the active-cover boundary to an end of the side margin portion in the first direction closest to the active-cover boundary among ends of the side margin portion in the first direction is defined as A1, and an average distance in the third direction from the first body-side margin boundary to an end of the side margin portion in the third direction closest to the first body-side margin boundary among ends of the side margin portion in the third direction is defined as A2, and then, A1/A2 is adjusted.