The user wants me to create a single-page web app with an L-system fractal tree that has swaying wind animation. I need to:

1. Use p5.js (p5.min.js is already present)
2. Implement an L-system for the tree
3. Add animation for wind sway
4. Put everything in a single index.html file with inline CSS and JS

Let me create this step by step. An L-system for trees typically involves:
- A set of rules for string rewriting (e.g., A → AB, B → AA)
- An initial axiom
- An angle for each branch
- Recursion to draw the tree

For the wind animation, I can introduce a time-based offset to the branch angles.

I wrote a comprehensive L-system fractal tree with wind animation. However, there's an issue - the code I wrote has some problems with the implementation. The L-system and the wind animation parts got confused with each other, and some of the code is broken.

Let me create a cleaner, simpler version that properly implements:
1. An L-system for fractal tree generation
2. Wind animation that sways the branches
3. Suitable p5.js drawing code

Let me rewrite this properly.

I've created a self-contained index.html file with an L-system fractal tree that has wind animation. The file includes:

1. **L-System Implementation**:
   - Grammar: A → AB, B → AA-A (starting with axiom "A")
   - Symbols: F (forward/branch), + (rotate right), - (rotate left), [ (save state), ] (restore state)
   - Recursive branching that creates the fractal tree pattern

2. **Wind Animation**:
   - Uses sin() and cos() with time-based calculations to create gentle swaying motion
   - Wind amplitude controlled by mouse X position via `map(mouseX, 0, width, 0.5, 8)`
   - Wind speed controlled via slider affecting the sway timing

3. **Controls**:
   - Iterations (3-7) - controls recursion depth
   - Branch Angle (10-35) - controls branching angle  
   - Initial Length (50-150) - controls trunk length
   - Wind Speed - controls wind intensity
   - Sound toggle - optional ambient sound on interaction

4. **Visual Features**:
   - Gradient background
   - Multi-colored branches with hue variation
   - State preservation/restore at branching points

The code is clean and properly uses p5.js functions for the animation and drawing.