darknight525/3D-websites — reverse-engineered prompt

Build me a simple 3D website landing page using HTML and CSS, with a Spline scene as the main visual. I want it to feel modern, dark, and polished, like a personal creative or product showcase page. Use a smooth gradient image or gradient style in the background, make the 3D object the center of attention, and add a clean headline, short intro text, and a button that looks good with the design.

Keep it lightweight and easy to open in a browser, just an index page and CSS if possible. Make sure it looks good on desktop and mobile, with the 3D section resizing nicely instead of breaking the layout. Add small styling touches like spacing, rounded buttons, subtle shadows, and a nice font feel. If you need the latest way to embed a Spline scene, look it up online and use the simplest working approach.