# Product Vision: “Keep My Weight” Tracker

## Vision Statement
Empower health-conscious individuals to effortlessly monitor and understand their weight journey and daily nutrition through a minimalist, privacy-first web app—delivering clear insights, seamless data portability, and an intuitive, distraction-free experience.

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## Target Audience
- **Health Enthusiasts** & people aiming for weight goals  
- Users seeking a **lightweight**, self-hosted solution  
- Privacy-minded individuals who prefer **local data storage** and full control  
- Non-technical users who appreciate a **zero-setup** interface  

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## Key User Needs
1. **Quick Weight Logging**  
   - Log weight in kilograms with minimal friction  
   - Separate weight entries from meal logs  
2. **Daily Meal Tracking**  
   - Record Breakfast, Lunch, Dinner, and “Other” items  
   - Flexible text fields, no calorie counting required  
3. **Progress Reporting**  
   - Clean, exportable charts & tables of weight evolution  
   - Ability to filter by date ranges  
4. **Data Portability & Backup**  
   - Import / Export complete data as JSON  
   - CSV export for spreadsheets or external analysis  
5. **Simplicity & Reliability**  
   - Zero-backend static site  
   - Dockerized for easy deployment via Coolify or similar  

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## Product Pillars

### 1. **Usability & Clarity**  
- **Single-page interface**: instant access to weight & meal logs  
- **Clean layout**: large inputs, clear typography, mobile-friendly  
- Save weight **independently** of meals  

### 2. **Insightful Reporting**  
- **Interactive weight chart**: line graph of weight over time  
- **Tabular view**: sortable, filterable by date  
- **Exportable**: CSV download or copy-paste  

### 3. **Data Ownership**  
- All entries stored in a single `data.json` file in root  
- **Import / Export** buttons for manual backup & restore  
- Encrypted if desired by advanced users  

### 4. **Lightweight Tech Stack**  
- **Site** built with vanilla JS (or minimal framework) + HTML/CSS  
- **Data layer**: read/write `data.json`  
- **Dockerized**: simple `Dockerfile` wrapping a static file server (e.g., Caddy, NGINX)  
- **Deploy**: Coolify recipe, GitHub → Docker → Cloud  

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## Minimum Viable Roadmap

| Phase | Deliverables |  
|-----|-------------|  
| **Phase 1** | • Weight log UI + persistence in `data.json`  
 | • Meal log UI (4 sections) + same JSON file  
 | • Save & Load from JSON via file picker  
| **Phase 2** | • Weight evolution line chart  
 | • CSV export of all entries  
 | • Date-range filters  
| **Phase 3** | • JSON import (merge vs overwrite)  
 | • Responsive mobile-first refinements  
 | • Docker & Coolify deployment docs  
| **Phase 4** | • Theming (light/dark)  
 | • Localization support  
 | • Retirement migration guide (e.g., to new data formats)  

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## High-Level Architecture

```text
┌─────────────────────┐      ┌───────────────┐
│  Web Server  │◀────▶│  data.json    │
│  (NGINX/Caddy)      │      │  (local FS)   │
└─────────────────────┘      └───────────────┘
        ▲      ▲
        │      │
        │      │
  Vanilla JS     HTML/CSS
 (UI & Data I/O)  
Frontend:

    ES6 modules, no build step (or minimal bundler)

    Fetch & download JSON via <input type="file"> / <a download>

Server:

    Containerized static file server

    Serves index.html, static assets, and data.json