Build a single-page **Sleep Debt Calculator** that helps users figure out how much sleep they owe themselves after a rough week.

The app shows a 7-day grid (Mon–Sun). For each day, the user enters how many hours of sleep they actually got (using a number input or a small +/- stepper). The app compares each day's entry against a user-adjustable "sleep goal" (default: 8 hours) and calculates:

- **Daily deficit or surplus** shown inline next to each row (e.g. `-1.5 hrs` in red, `+0.5 hrs` in green)
- **Total weekly sleep debt** displayed prominently at the bottom (e.g. `You owe yourself 4 hours of sleep`)
- A simple visual bar or progress indicator showing how close the user is to their weekly goal

All entries live only in the page (no backend, no auth). Include a **Reset** button that clears all inputs back to zero. The sleep goal input should update all calculations instantly as the user types. The whole experience fits on one screen with no scrolling on a typical laptop display.