How to troubleshoot brake fluid leak in an Audi A3?

I noticed a small puddle of brake fluid under my Audi A3. How can I determine where the leak is coming from and what steps should I take to fix it?

First, check the brake lines and connections for any visible signs of leakage. If you don't see anything, you can try applying pressure to the brake pedal and see if the leak worsens. If it does, the issue is likely with the brake cylinder or a brake line. If the leak does not worsen, the issue may be with the master cylinder or brake booster. In either case, it's best to take your Audi A3 to a certified mechanic for further diagnosis and repair.