Clutch not engaging

Today while driving home, our daughters clutch stop engaging completely with no warning - vehicle only has 30,000 miles and she is a great driver and doesn't ride the clutch. You can press the pedal all the way to the floor. It pops right back up. We are having a heck of a time finding exploded views and installation information online. We do not see any leaking and her car is parked in a garage every night. We are usually pretty savvy at doing repair work ourselves but would love some guidance on where to find images to show us where all of the clutch parts are located so we can rule out items and get her back on the road.
Looks like it's either a problem with master or slave clutch cylinder. It's an hydraulic clutch and it share the same fluid reservoir than the brakes.