Why daytime running lights shut off in my 2007 Toyota Camry when the engine is off?

The daytime running lights (DRL) in your 2007 Toyota Camry are designed to turn off when the engine is off to conserve battery power. When the engine is running, the alternator generates electricity that powers the car's electrical systems including the DRL. When the engine is off, the battery supplies power to the lights, and shutting them off helps to prevent it from being drained.