# Sprint 4: UI/UX & Frontend Decisions

## Overview
Sprint 4 focused on transitioning the application from a basic prototype to a modern, user-friendly web interface while adhering to the local-first philosophy.

## Technical Choices
*   **Vanilla Stack**: We chose **HTML/Vanilla CSS/Vanilla JavaScript** instead of a heavy framework like React or Vue. 
    *   *Reasoning*: Reduces dependency overhead, keeps the local server incredibly lightweight, and simplifies deployment on the VM without needing Node.js build steps.
*   **Design System**:
    *   Implemented a CSS variables (`:root`) design system for easy theming (Glassmorphism, dark/light modes).
    *   Added micro-interactions (hover states, smooth fading transitions) to improve perceived performance and user delight without relying on heavy external animation libraries.
*   **State Management**:
    *   Used simple DOM manipulation and `localStorage` for managing the auth token and UI transitions between the "Login Screen" and the "Chat Interface."

## Key Deliverables
*   `static/style.css`: Contains all custom animations and glassmorphism styling.
*   `static/script.js`: Handles all frontend API interactions (login, chat streaming, searching).
*   `static/index.html`: The single-page application skeleton.