🌊 Ambient Effect — AI Prompt📋 Copy Prompt

Act as an expert technical artist. I am building a custom RGB Keyboard Lighting Engine using JavaScript.
I need you to write a mathematical lighting effect based on my request.

This is an AMBIENT effect: it plays continuously, driven only by time and key position — it has no idea when keys are pressed.

### ⚙️ ENGINE SPECS
You only need to write the logic for a single keycap, called every frame. You have access to:
1. `nx` (0.0 left to 1.0 right), `ny` (0.0 top to 1.0 bottom)
2. `t` (Continuous time in seconds)
3. `params` (Object containing GUI variables)
4. `fmod(a,b)` (Use this instead of the % operator for floats)

### 🎛️ GUI PARAMETERS (MANDATORY)
You MUST ALWAYS include a JSON block at the VERY TOP of your code wrapped in `/*CONFIG` and `CONFIG*/` to expose settings to the user.
Supported types: "slider", "color", "select".

Example:
/*CONFIG
{
  "speed": { "type": "slider", "min": 0, "max": 10, "value": 2.5, "step": 0.1 },
  "color": { "type": "color", "value": "#00ffcc" },
  "direction": { "type": "select", "options": {"Left": 1, "Right": -1}, "value": 1 }
}
CONFIG*/

### 📜 STRICT RULES
- Write pure JavaScript. No external libraries.
- DO NOT use the `**` operator. Use `Math.pow(base, exp)`.
- DO NOT use the `%` operator. Use `fmod(a, b)`.
- Write all numbers with a decimal point (e.g., `1.0` instead of `1`) for safe C-transpilation.
- Use `params.speed` or `params.color` inside your code.
- End your code by returning a valid CSS color string (e.g., `rgba(r,g,b,a)`, `hsl(h,s,l)`, `rgb(r,g,b)`, or hex), or return 'transparent' to leave the key unlit.
- Helper functions can be defined at the bottom.

### 🎯 MY REQUEST
I want an ambient effect that looks like: [INSERT EFFECT]

⚡ Reactive Effect — AI Prompt📋 Copy Prompt

Act as an expert technical artist. I am building a custom RGB Keyboard Lighting Engine using JavaScript.
I need you to write a REACTIVE lighting effect: it fires from the physical key(s) the user actually presses, and fades out over time. It runs alongside (or instead of) an Ambient layer.

### ⚙️ ENGINE SPECS
You write the logic for a single keycap, called every frame. You have access to:
1. `nx` (0.0 left to 1.0 right), `ny` (0.0 top to 1.0 bottom) — this key's own position
2. `t` (Continuous time in seconds)
3. `params` (Object containing GUI variables)
4. `fmod(a,b)` (Use this instead of the % operator for floats)
5. `reactive` — info about recent key presses, shaped like this:
   - `reactive.held` — true if THIS exact key is currently being physically held down
   - `reactive.count` — number of currently active (not-yet-decayed) presses
   - `reactive.nearest` — closest active press to this key, or null if none:
       { dist, age, dx, dy }
       - dist: distance (same 0–1 scale as nx/ny) from this key to the pressed key
       - age: seconds since that key was pressed (0 = just now, grows every frame)
       - dx, dy: signed offset (this key minus the pressed key), for directional effects
   - `reactive.presses` — ALL active presses in the same shape as `reactive.nearest`, sorted nearest-first (use this to support chords / multiple simultaneous keys)

### 🎛️ GUI PARAMETERS (MANDATORY)
Same as ambient — a `/*CONFIG ... CONFIG*/` JSON block at the very top exposing "slider", "color", or "select" controls.

### 📜 STRICT RULES
- Write pure JavaScript. No external libraries.
- DO NOT use the `**` operator. Use `Math.pow(base, exp)`.
- DO NOT use the `%` operator. Use `fmod(a, b)`.
- Always guard against `reactive.nearest` being null (or `reactive.count` being 0) before using it, and return 'transparent' when there's nothing to show — this lets the layer underneath (Ambient, or the dark background) show through.
- Use `age` to fade the effect out over a duration you expose as a `params` slider (e.g. `params.duration`).
- End your code by returning a valid CSS color string, or 'transparent'.
- Helper functions can be defined at the bottom.

### 🎯 MY REQUEST
I want a reactive (keypress-triggered) effect that looks like: [INSERT EFFECT]