### Context
- **Brand name**: {{brand_name}}
- **Primary color palette** (hex, optional): {{primary_colors}}
- **Secondary color palette** (hex, optional): {{secondary_colors}}
- **Visual style keywords** (e.g., geometric, organic, abstract, techy): {{style_keywords}}
- **Intended use** (e.g., slide deck, Power BI dashboard, website hero): {{use_case}}

### Task
1. Generate a **single high‑resolution (minimum 4096×4096 px) tileable texture** that reflects the brand’s visual language.
2. The texture must be **seamless** when repeated both horizontally and vertically.
3. Include **contrast guidelines**: ensure the texture does not overpower foreground text or data visualizations (max 30 % opacity‑equivalent visual weight).
4. Provide **two variants**:
   - **Light mode** – suitable for dark‑text overlays.
   - **Dark mode** – suitable for light‑text overlays.

### Output Format
- Return a markdown block with two image URLs (or base64 placeholders) labeled *Light* and *Dark*.
- Follow with a short **spec sheet** (JSON) containing:
  ```json
  {
    "width": 4096,
    "height": 4096,
    "format": "PNG",
    "seamless": true,
    "color_palette": ["#…", "#…"],
    "style": "{{style_keywords}}",
    "notes": "Designed for {{use_case}}"
  }
  ```

### Quality Bar
- **Resolution**: ≥ 4096×4096 px, lossless PNG.
- **Seamlessness**: Verify by tiling the image 3×3; no visible seams.
- **Brand fidelity**: Colors must match the supplied palette within ΔE < 2.
- **Visual balance**: Background should be subtle (average luminance variance < 15 %).

### Constraints
- No recognizable copyrighted patterns (e.g., famous logos, trademarked textures).
- Avoid overly busy details that could distract from overlay content.
- Keep file size < 5 MB per variant.
- Use only the models listed; do not invoke external APIs.

---
**Ready‑to‑copy Prompt**
```text
You are a brand‑focused visual designer. Create a seamless, tileable texture for the brand "{{brand_name}}".

Palette: {{primary_colors}} {{secondary_colors}}
Style: {{style_keywords}}
Use‑case: {{use_case}}

Produce two PNG images (4096×4096): one optimized for light‑text overlays (Light mode) and one for dark‑text overlays (Dark mode). Ensure strict seam‑lessness, color accuracy (ΔE < 2), and a subtle visual weight (≤ 30 % opacity‑equivalent). Return the images as markdown links followed by a JSON spec sheet.
```