Is it a foul to step on the springboard in the long jump? And the rules of long jump

The springboard is for you to step on, but your feet can't go beyond the front of the springboard. During the competition, a piece of cement with a width of 10 cm will be placed in front of the springboard. Your feet can't leave any marks on this cement, otherwise it's a foul.

You can't draw a schematic diagram here, just remember that you can step on the springboard, but you can't.

There is also the measurement of long jump performance, taking the distance between the front edge of the springboard and the trace left by your body in the bunker closest to the springboard as your actual performance. In other words, it's not the distance from your foot to the springboard, but the recent trace.