Hey, that’s a cool idea—let’s keep it light and hands‑on so students can see the math in action. I’d start with a web‑based stack: use Three.js for 3‑D rendering and maybe a small physics engine like Cannon.js or even a custom N‑body solver in JavaScript; that way everyone can just drop the HTML into a browser. Pair it with D3 for the dark‑matter heatmap overlay and a simple UI to tweak parameters. If you want something more code‑heavy, a Python Jupyter notebook with Matplotlib for 2‑D slices and a tiny N‑body routine written in NumPy is perfect for showing the math under the hood. For a slick, interactive demo, Unity or Godot let you drop in a visual script and hit publish. Pick the tool that matches your team’s skill level and your timeline—don’t over‑engineer it, or you’ll lose the “learning by doing” vibe.

That plan feels just right—no heavy tooling, just the core math and a splash of color with D3. Students will love watching gravity play out in real time and instantly seeing the dark‑matter halo pop up. You can keep the N‑body loop tiny, maybe a simple velocity‑Verlet, and then feed the positions straight into Three.js meshes. A slider to tweak the dark‑matter fraction would let them see how the invisible mass scaffolds everything. Keep the code clean, comment the equations, and you’ve got a live, interactive textbook in a browser. Let’s prototype a single‑particle demo first and then scale up—keeps the momentum going and the debugging fun.