## Feature 001: Focus session with visual countdown

**Sources:** focus-session-with-visual-countdown, visual-distinction-between-focus-and-break, sound-notification-at-session-end
**Personas:** knowledge worker seeking uninterrupted focus time
**Stack span:** full-stack
**Tier:** v1

**Description:**

User starts a focus timer, sees remaining time count down visually, receives notification when the session ends.

**Constituent tickets:**
- focus-session-with-visual-countdown
- visual-distinction-between-focus-and-break
- sound-notification-at-session-end
