Floor heating fengshui
It's just not pretty. In fact, there is a saying that the entrance is getting higher and higher, and it is not good to go down. But if you put a red marble (China red or Indian red) on the threshold, or pad two marbles, the floor of your room will be as high as the threshold, or the threshold will be slightly higher than the indoor one, which is both beautiful and beneficial to wealth. Red marble has the meaning of getting brighter as you step on it.