## Story 001: Start and complete a focus session

**Persona:** Marcus, 28, a freelance writer who works from home and loses track of time in deep focus. He wants structure without rigidity.

**Situation:**

Marcus sits down to write a client brief. He knows he works best in uninterrupted blocks but often forgets to break. He opens the pomodoro app.

**Need:**

As Marcus, I want to start a 25-minute session with one click and receive a clear notification when it ends, so that I can trust the timer and stop watching the clock.

**Acceptance:**
- Marcus can start a session from the home screen with a single tap
- The app shows remaining time clearly and updates in real-time
- At 25 minutes, Marcus receives a notification (sound + visual) that interrupts his focus deliberately
- The notification makes clear the session ended; he can immediately start a break or begin a new session

**Tier:** core

**Confusion-flags:**
- I assumed 'notification' means a phone alert, but what if Marcus is on a desktop? Do we need platform-specific behavior, or is browser notification enough?
- The phrase 'sessions are saved' — does this happen automatically, or does Marcus have to confirm? Automatic feels right, but I'm not certain.
- What happens if Marcus closes the app mid-session? Does the timer continue in the background, or does the session reset? This might be a platform question.
