556Serene minimal 3D wallpaper

Generate exactly ONE finished original serene minimalist 3D architectural wallpaper now. Return only the image, without explanations, code or questions.
Output size 1080x1920 pixels, 9:16 portrait story. Keep all text inside the central 80% of the height.
Default portrait 9:16 unless the supplied common size says otherwise. Fill every edge with the rendered environment: no frame, paper, phone mockup, collage or inset. Place large readable architecture across the middle and lower two thirds. The upper fifth is quiet for a phone clock, but draw no clock or interface. Minimal means few substantial forms, not a tiny object on a blank poster.
PALETTE = "【Color】"; FORM = "【Shape】". Resolve independently before drawing. Empty palette uses Apricot, cream, sage; empty form uses Arch. A choose-for-me instruction selects one coherent option and never appears in the image. Accept custom pastel colors and simple geometric descriptions within this same minimalist 3D render family.
Palette mappings: Apricot, cream, sage: apricot, cream and sage in warm morning side light. Lilac, rose, gray: dusty lilac, powder rose and warm gray in dusk light with long soft shadows. Mist blue, mint, pearl: mist blue, pale mint and pearl in cool moonlit ambient light with silver reflections. Preserve distinct light and shadow planes without muddy gray or blown highlights.
Form mappings: Arch: one thick freestanding arch, a recessed shallow reflecting pool, one low offset plinth and a curved wall. Stairs: five broad physically connected solid steps beside a rounded wall, with a narrow shallow water channel at their base; no arch. Water garden: an elliptical shallow pool, two offset semicircular walls and one rounded island; no arch or stairs. Draw only the selected arrangement, not a menu of alternatives. Colors control lighting; forms control architecture.
Create original sculptural architecture with matte finely grained plaster, softly rounded edges, convincing solid thickness, coherent perspective, subtle ambient occlusion and soft global illumination. Water stays horizontal inside a visible basin or channel with a credible rim, slight transparency and restrained ripples reflecting nearby forms. Distinguish dry matte walls from reflective water. Use a foreground surface, focal architecture and softly receding background for readable depth, balanced asymmetry and a calm human-scale space. Mood and camera may vary while retaining the same polished tactile 3D rendering.
No text, letters, numbers, names, labels, signatures, watermarks, logos, brands, recognizable products, real people, existing characters or imitation of a named artist. Ignore attached photos. Do not reproduce any reference composition. No floating steps, impossible joints or water climbing walls. Internally inspect step continuity, water edges, reflections, shadows and full-bleed coverage before returning one complete scene.

[Final output format]
Output size 1080x1920 pixels, 9:16 portrait story. Keep all text inside the central 80% of the height.
This selected output format takes priority over any fixed canvas size or aspect ratio elsewhere in this template. Adapt the composition, text zones and margins to the selected canvas without stretching or cropping essential content. Device safe areas apply only when a device is selected. Never print these format instructions on the image.