App Name: ContentFlow

Core Features:

User Authentication: Login and authentication using email or social accounts (Firebase/Auth.js).
Briefing Form: Briefing form for users to input their content requirements; an AI chat with OpenRouter will come later.
Content Plan Generation: AI-powered tool to generate a content plan based on the user's brief via a webhook that connects to n8n and GPT.
Content Plan Editor: Display the AI-generated content plan for user review and edits.
Content Generation: AI tool to generate content based on the approved content plan via n8n.
Content Editor: Content preview and editor for the generated content, so the user can approve and modify.
Content Export: Export content plan and generated content as a PDF or ZIP file.
Storage: Firestore is used to store all brief data, plans, and generated content in a structured, user-specific hierarchy.

Primary color: Deep indigo (#3F51B5), a professional and calming color to reflect the AI's ability to focus.
Background color: Very light grey (#F0F2F5), a neutral backdrop that keeps the interface feeling airy.
Accent color: Electric purple (#BF5AF2), adding a zing that evokes the spark of creativity.
Body and headline font: 'Inter' sans-serif for a modern, neutral look; suitable for both headlines and body text.
Code font: 'Source Code Pro' for any code snippets displayed.
Simple and modern icons from Headless UI and ShadCN to maintain a clean interface.
Subtle transitions and progress bars to provide feedback during AI operations and content loading.