Créez un système complet de gestion de startup dans un seul fichier HTML

Voici la traduction en français du cahier des charges, en respectant toutes les contraintes (placeholders, structure, etc.) : Build a complete, functional startup management system in a single HTML file using HTML, CSS, and JavaScript. WHAT IT DOES A system that acts as your CEO and product launch manager. You define the product, audience, and goals. The system handles everything else: product specs, copy, marketing plan, launch timeline, and task management, all in one place. CORE FEATURES 1. Startup Dashboard - A clean overview showing: Launch countdown, Tasks by status, Key metrics (revenue goal, users, launch readiness), Recent activity - Quick-add buttons for tasks, milestones, and notes - A progress bar showing overall launch readiness 2. Product Definition - Define your product with: Name, One-line description, Target audience, Problem it solves, Key features (list), Revenue model, Launch date - Edit and update any field - A "Product Brief" view that compiles everything into a single, shareable document 3. CEO Task Management - Tasks are auto-generated from your product definition - Group tasks by: To Do, In Progress, Review, Done - Tasks include: Title, Description, Priority, Assignee (AI or human), Due date, Dependencies - Add custom tasks manually - Drag and drop to change status 4. Launch Plan & Timeline - A visual timeline showing key launch milestones - Auto-generated launch phases: Product Development, Marketing Prep, Pre-Launch, Launch Day, Post-Launch - Each phase has a checklist of tasks - Countdown to launch day with visual urgency 5. Copy & Content Generator - Generate: Product description, Tagline, Elevator pitch, Value proposition, Email copy, Social media posts - Edit and save generated copy - Export copy as plain text or formatted document 6. Marketing & Outreach - Define target channels (Social, Email, Ads, PR) - Auto-suggest marketing activities based on your product - Track outreach status: Not Started, In Progress, Done - Notes on each channel 7. Metrics & Goals - Set goals: Revenue, Users, Sign-ups, Engagement - Track progress with visual charts - Update metrics manually - View projected vs actual 8. Notes & Brainstorming - A dedicated space for ideas, feedback, and random thoughts - Tag notes by: Product, Marketing, Launch, Operations - Search through all notes 9. Customization - Light mode / Dark mode toggle - Customize primary color - Edit or hide sections you don't need 10. Data Persistence - All data saved to localStorage - Export all data as JSON - Import data from JSON backup LAYOUT - Left sidebar: Navigation (Dashboard, Product, Tasks, Launch Plan, Copy, Marketing, Metrics, Notes) - Main area: Content based on selected view - Top bar: App name, launch countdown, dark/light toggle TECHNICAL REQUIREMENTS - Single HTML file with embedded CSS and JavaScript - Responsive: works on desktop and tablet - Smooth animations and transitions - Clean, modern, professional aesthetic - No external dependencies (use vanilla JS) Build a polished, functional startup management system that someone would actually want to use to launch their product.