Narrow beam or curtain motion detector

I’m looking for a compatible curtain motion detector. My use case is a stairway. Walking next to the stairway, no detection. On the stairway, detection. To turn on light for a set time. I have wooden, slippery stairs of death in my house and would like to force the overhead lights on. Wifi, Zigbee, Z-Wave are all good. Thx.