Workout timer for your routine

Use with: build-web-app. Resume line when done: Built {project_name}, an interval timer for my training routine — live at {url}

Brief

An interval timer with your own routine hardcoded first and editable second: your sets, your work intervals, your rest lengths. Big numbers readable from the floor, a loud beep at each transition, and controls big enough to hit with a sweaty thumb on a phone. The routine persists across reloads (localStorage is fine).

Personalize

• Your routine, exactly. The circuit or set scheme you did last week, with its real rest times. If you rest 90 seconds between sets, the default is 90, not 60.
• The floor test. Every design decision gets checked from where you train: phone on the ground, you mid-exercise, one glance to know where you are. Font sizes and colors answer to that test.
• The sound. Pick a beep you can hear over your own music and make the last three seconds count down audibly so you never watch the screen.

Milestones

1. Write your routine in the README as data: exercises, durations, rests, rounds. That structure becomes the app's model.
2. A timer that runs your hardcoded routine start to finish with pause and reset, deployed. Ugly is fine.
3. The beep, plus the big-number display that passes the floor test.
4. Edit mode: change durations and add or remove exercises in the browser; the routine survives a reload; empty state designed.
5. Edge cases: screen staying awake during a session, a paused timer surviving an accidental reload, zero-length rests skipped cleanly.
6. Train with it for a week. Final README with what you changed after real workouts.

Done means

• Live URL responding; the routine survives a reload
• A full session runs hands-free with audible transitions
• Editing works; empty state is designed
• You trained with it for at least a week, noted in the README
• At least 10 commits across at least 7 distinct days, authored by you
• SESSIONS.md has an entry per session, written by you