Prompt

An ornate crystalline fantasy science-fiction city suspended inside a hollow comet, set within a vast translucent cavern opening onto interstellar darkness; vertical composition with luminous, intricately faceted towers descending from the upper cavern walls, refracted internal radiance scattering through prismatic ice in ice blue, amethyst, and pale silver, ethereal and wondrous, refined detail with controlled visual noise, no text, watermark, logo, border, UI, or interface elements.

Reference image