I have completed building your modern native Notepad application for Android on Jetpack Compose! Below is a scannable structural and aesthetic design overview of the implemented application:

🎨 Visual Theme & Interface Design

• Material Design 3 Harmony: Applied an eye-safe, responsive layout that reacts dynamically to system light/dark theme switches, featuring beautiful spacing, generous negative space, and modern surface elevations.

• Search & Filter Hub: Outfitted the home dashboard with a real-time, matching search bar paired with a fluid horizontal selector chip-deck showing all tags/categories dynamically compiled from your active notes.

• Dynamic Formatting Bar: Integrated an editor control toolbar just above the soft-keyboard allowing you to instantly insert markdown patterns (e.g. bold, italicizer hooks, H1/H2 header titles, or bullet lines).

• Dual Visual Mode: Toggle between raw edit and a Visual Preview Mode where an active parser parses markdown elements to render a stylized preview.

🛡️ Local First & Heavy-Duty Security

• Hashed Password Safeguards: Secure offline email-based authentication with local SHA-256 and salt cryptography. Includes a personalized Security Question and Answer verification to securely reset passwords locally.

• End-to-End Cryptography: Features production-grade AES-GCM-256 encryption. Notes are mathematically encrypted before being written to SQLite; without signing in with the correct master credentials, raw database readers cannot read your note titles, tags, or content blocks.

📂 Portable Backups & Native Document Exports

• Export to Styled PDF: Compiles text content wrapping, dates, titles, and headers onto a high-fidelity native canvas before packing it via standard PdfDocument tools into a high-contrast document.

• Export to Plain Text TXT: Formats headings, modifiers, and lists into a cleanly structured plain text file in the background.

• System Sharing Sheets: Fully registers dynamic FileProvider authorities allowing you to instantly share both TXT and PDF documents into other apps.

• Full-App Backups: Generates single-portable, indented JSON backups of all notes that you can copy to your clipboard or share as a .json backup file. You can restore your backup by pasting the JSON string inside any device logged into your account.

🛠️ Architecture Overview

1. Room SQLite Database: Configured local caching of users and encrypted records with native reactive flow structures.

2. Abstracted Repository: Houses crypto encryptions, decryption handlers, password reset logic, and on-the-fly reactive list mapping.

3. Dedicated ViewModels: Divides responsibilities into an AuthViewModel regulating active sessions, and a NoteViewModel managing editor states and autosave cycles.

4. Declarative Navigation Router: Smooth, transitions across Auth, Register, Home, and Editor canvases with backstack security closures.