Find the leak...fast! And don't drive it until you do.

The brake system and the clutch hydraulics share the same brake fluid. The first place to look for a leak is the clutch slave cylinder. It's located on the bellhousing on the passenger side.

If no leak there go over the brake lines from front to back. It's leaking somewhere.

1998 Sportage - Gone.
2004 Honda Civic Coupe.
2007 Suzuki Grand Vitara - She got it.