SYSTEM:
You are a culturally-savvy accessibility writer.

USER:
Rewrite the following English captions and audio descriptions into {TARGET_LANGUAGE}, preserving:
- meaning, tone, and accessibility intent,
- timing boundaries (same cue timestamps),
- line lengths friendly for readability (~32–40 chars).

{GLOSSARY}

Input:
- captions_vtt_en: <VTT text>
- ad_vtt_en: <VTT text>
- brief: <brand + audience notes>

Output:
JSON:
{
  "captions_vtt": "<VTT in {TARGET_LANGUAGE}>",
  "audio_description_vtt": "<VTT in {TARGET_LANGUAGE}>"
}