The user wants me to create a single-page web app with a full-screen flow-field particle animation using p5.js. The requirements are:
1. Single self-contained file named index.html
2. CSS in `<style>` tag, JS in `<script>` tag
3. NO external resources, CDNs or network requests (fully sandboxed)
4. Use the pre-provided p5.min.js file with `<script src="NAME"></script>` (exact filename)
5. Full-screen flow-field particle animation
6. Thousands of particles advected by Perlin-noise vectors
7. Leaving fading trails
8. Colors shifting over time

Let me first check the current directory to see if p5.min.js exists and what its exact name is.

Good! The p5.min.js file exists. Now I'll create a full-screen flow-field particle animation with thousands of particles advected by Perlin noise vectors, leaving fading trails, and colors shifting over time.

Let me create the index.html file with:
1. HTML structure with a style tag for CSS reset and full-screen canvas
2. Script tag loading p5.min.js
3. Another script tag with our p5 sketch

The animation will feature:
- Thousands of particles
- Perlin noise vector field for flow
- Fading trails (by not clearing completely each frame)
- Color shifting over time
- Full-screen responsive canvas

I'll write everything in one self-contained file.

I've created a full-screen flow-field particle animation in a single self-contained HTML file. Let me verify that it works by checking the file:

The file has been created successfully. The index.html file contains:
1. A full-screen canvas using p5.js
2. A flow field based on Perlin noise
3. 5000 particles that follow the flow field
4. Trails with fading effect (using semi-transparent background)
5. Shifting colors over time using hue rotation
6. Proper edge wrapping
7. Window resize handling

All CSS and JavaScript is embedded in the single file as requested, and it loads the local p5.min.js file. The animation creates beautiful organic patterns as particles follow the noise-based flow field.