C182 pilot reported ATC cleared aircraft to and hold short of the takeoff runway. Aircraft crossed over the runway hold short line.

Narrative

We were given taxi clearance for RWY XX via 1 2 hold short RWY XX . At arrival to hold short line the AC (Aircraft) was stopped. It started to roll and was again stopped however we had crossed the hold line.After stopping at hold line by pilot flying; I ; as PIC ;diverted my attention. Sensing the ac was moving brakes were applied; however we had crossed the hold short line.I must be more vigilant to assure that this never occurs again.