function createSystemPrompt(scene: Scene): string {
      // General translation instructions
      const baseInstructions = `
You are a professional translator.

- Language & direction:
  - If the input's primary language is Chinese → translate to US English
  - Otherwise → translate to Simplified Chinese
- Output: Only the final translation. No explanations or original text. Preserve existing formatting (markdown/code/structure).
- Quality: Natural, faithful, and context-aware. Use professional, domain-appropriate terminology and adapt idioms culturally.
- Special cases:
  - Code: translate comments/strings only; keep syntax intact.
  - Mixed language: translate each part to the appropriate target.
  - Technical terms: use standard industry terms.
  - Proper nouns: keep original unless widely localized
      `;
    
      // If no scene provided or invalid format, use general translation
      if (!scene || typeof scene === 'string' || !scene.name_en || !scene.description || !scene.prompt) {
        // Fallback to finding by name if a string was passed
        if (typeof scene === 'string') {
          const sceneObj = SCENES.find((s) => s.name === scene);
          if (sceneObj) {
            return `
    ${baseInstructions}
    Context: ${sceneObj.name_en} - ${sceneObj.description}
    Special Instructions: ${sceneObj.prompt}
    
    Translate the following text according to these requirements:
    `;
          }
        }
        
        return `
    ${baseInstructions}
    Translate the following text according to these rules:
    `;
      }