Here is a complete, single-file HTML solution using Three.js. You can save this code as an `.html` file (e.g., `seastead.html`) and open it in any modern web browser.
I have designed it so the hull is semi-transparent, allowing you to see the 5 internal floors as described.
```html
Wing-Spar Seastead 3D Model
Wing-Spar Seastead Design
Left Click: Rotate | Right Click: Pan | Scroll: Zoom
```