ELI5: Why Does The Moon Look Bright and Crisp Until the Exact Moment the Sun Comes Up?

In the morning when the moon is still out and the sun is coming up but hasn't gotten above the horizon yet, the moon looks so bright and crisp in the sky, no matter how bright the sky already is. As soon as the sun is above the horizon, the moon looks pale and faded, though. Why does it look so different depending on where the sun is in relation to the horizon?