Build an Idea Tracker That Visually Fades Unused Ideas Over Time

Build a real, usable micro web app called Idea Half-Life that helps users capture ideas and watch them fade over time unless they intentionally revisit them.

This is not a to-do list.
This is not a note app.
This is a natural selection system for ideas.

The app should feel calm, modern, and slightly emotional—like watching thoughts evaporate.

⸻

🧠 Core Concept (Unique Twist)

Every idea has an attention half-life.

If the user does nothing, the idea gradually fades:
• visually (opacity, blur, “ink drying out”)
• structurally (it sinks lower in prominence)

If the user revisits an idea, it “survives” and regains clarity.

No reminders.
No notifications.
No guilt.

The interface should communicate:

“Ideas that matter tend to return.”

⸻

✍️ Core Features (Must Have)

1) Capture
• One clean input field: Title + optional one-line note
• Press Enter to save (keyboard-first)
• Ideas appear instantly in the list

2) Half-Life Decay System
Each idea stores:
• created timestamp
• last revisited timestamp
• decay setting (half-life duration)

Default half-life: 7 days
Allow per-idea half-life options:
• 1 day
• 3 days
• 7 days
• 14 days
• 30 days

Decay affects:
• card opacity
• slight blur
• saturation drop
• “paper aging” texture effect (subtle)

When an idea reaches near-zero visibility:
• it doesn’t disappear immediately
• it becomes “ghosted” at the bottom (still recoverable)

3) Revisit Ritual (Not a Like Button)
To refresh an idea, require a small intentional action:
• click and hold “Revisit” for 1.5 seconds
or
• press and hold the spacebar while focused

On revisit:
• fade animates back in
• “last revisited” updates
• the idea gently floats upward again

4) Views
Provide 2 views:
• Garden View (default): ideas as living/fading cards
• Archive View: compact list with filters (Active, Fading, Ghosted)

5) Search + Filters
• Search by title text
• Filter by state:
• Fresh
• Fading
• Ghosted

No sorting by “priority”.

6) Local-First Data
• Use localStorage
• Works offline
• Export/Import JSON
• Clear all data with confirmation

⸻

🎨 UX & Visual Style (Important)
• Calm minimalist UI
• Soft shadows, rounded cards
• Smooth transitions (opacity, blur, gentle drift)
• Light/Dark mode toggle saved to localStorage
• Subtle microcopy, no “productivity language”

Ideas should feel like:
• sticky notes losing ink
• sketches fading in a notebook
• a “memory garden” not a database

⸻

🛠 Technical Requirements
• Single HTML file
• Embedded CSS + JavaScript
• No external libraries
• Clean, commented code
• Include a CONFIG section for:
• default half-life
• decay curve (linear vs exponential)
• theme defaults
• animation intensity

Use an exponential decay model like:
• visibility = 0.1 + 0.9 * exp(-k * days_since_revisit)
(where k is derived from half-life)