1994 Honda Civic Master cylinder or slave cylinder. Where l

Transmission problem
1994 Honda Civic 4 cyl Front Wheel Drive Manual 114k miles

Over the last few days my clutch pedal has gone closer and closer to the floor without disengaging the clutch. Yesterday, it went all the way to the floor. Called my mechanic and he said to put brake fluid in the resevoir and that I had a leak somewhere. Did that and pumped the clutch for a while. Started working again. This morning, the level was lower again. So it seems to be leaking when the car is sitting. If it is the slave or master cylinders, where are they located on my car?