Build a Second Brain: Personal Knowledge Management System

Build a complete, functional personal knowledge management system in a single HTML file using HTML, CSS, and JavaScript. WHAT IT DOES A personal knowledge management system, your external brain. It captures, organizes, and connects everything you need to remember: notes, tasks, projects, ideas, and relationships between them. Think of it as a second brain that never forgets. CORE FEATURES 1. Dashboard (Home View) - A clean overview showing: Today's tasks, Recent notes, Active projects, Quick stats (total notes, tasks done, active projects) - A daily prompt: "What's one thing you want to remember today?" - Quick-add buttons for notes, tasks, and projects - Activity feed showing recent changes 2. Notes & Knowledge Base - Create rich-text notes with: Title, Content, Tags, Project Association - Organize notes by: Projects, Tags, Date created, Date modified - Search across all notes by title, content, or tags - Link notes to each other (like a wiki) - Auto-save as you type - Version history: view previous versions of a note - Export note as Markdown or plain text 3. Projects - Create projects with: Name, Description, Status (Active, On Hold, Completed), Deadline - Attach notes, tasks, and ideas to each project - Project progress bar showing completion - View all projects on a board or list 4. Tasks & Action Items - Create tasks with: Title, Description, Due Date, Priority (High/Medium/Low), Project Association - Group tasks by: Today, This Week, Later, or Project - Mark tasks as complete with visual feedback - Subtasks: break tasks into smaller steps - Recurring tasks: daily, weekly, monthly - Reminders: set notifications for due tasks 5. Ideas & Quick Capture - A dedicated "Inbox" for capturing thoughts before organizing them - Quick-add from any view using a floating button or keyboard shortcut - Auto-tagging: suggest tags based on content - Later: move ideas to a "Someday" list 6. Connections & Relationships - Link notes to projects, tasks to notes, ideas to tasks - A visual map showing how everything is connected - "Related to" section on every item 7. Daily Review - Morning review: what to focus on today - Evening review: what got done, what to carry over - Weekly review: what's working, what's not - AI-generated summary of your week 8. Customization - Light mode / Dark mode toggle - Customize: primary color, default view, daily prompt settings - Organize the sidebar to show what you use most 9. Data Persistence - All data saved to localStorage - Data persists across browser sessions - Export all data as JSON - Import data from JSON backup LAYOUT - Left sidebar: Navigation (Dashboard, Inbox, Notes, Projects, Tasks, Map, Settings) - Main area: Content based on selected view - Top bar: App name, search bar, quick-add button, dark/light toggle TECHNICAL REQUIREMENTS - Single HTML file with embedded CSS and JavaScript - Responsive: works on desktop and tablet - Smooth animations and transitions - Clean, minimal, distraction-free aesthetic - No external dependencies (use vanilla JS) Build a polished, functional second brain that someone would actually want to use every day.