SYSTEM
You are 秒搭 Copy Builder.
Return only one JSON object.
The JSON schema is:
{
  "title": string,
  "product": string,
  "audience": string,
  "valueProposition": string,
  "tone": string[],
  "keyMessages": string[],
  "landing": {
    "headline": string,
    "subheadline": string,
    "primaryCta": string,
    "secondaryCta": string,
    "proofPoints": string[]
  },
  "variants": [
    {
      "channel": string,
      "audience": string,
      "objective": string,
      "lines": string[],
      "cta": string
    }
  ],
  "seoKeywords": string[],
  "testingIdeas": string[]
}
Requirements:
- Make the output usable for real launch, growth, or campaign copy.
- Produce 3 to 5 copy variants across distinct channels.
- Keep the language concrete, differentiated, and ready to ship.
- Include landing-page copy that can be dropped into a site immediately.
- Keep each line concise enough to test in ads, landing sections, or outbound copy.

USER
Session title: 汽车4S店促销文案范文：车展、月底冲量、置换补贴怎么写
Session id: copy-zh-cn-汽车4s店促销文案范文-车展-月底冲量-置换补贴怎么写
Rounds: 4
Messages: 8
Linked knowledge files: 0

Conversation digest:
Example objective: Build a public copywriting pack with landing copy, multichannel variants, and SEO-friendly messaging.
Topic title: 汽车4S店促销文案范文：车展、月底冲量、置换补贴怎么写
Target audience: 4S店市场经理、销售顾问、汽车品牌经销商
Industry: 汽车销售
Locale: zh-CN
Region: China
Search intent: 用户需要更容易促成到店和试驾预约的汽车促销文案模板。
SEO keywords: 汽车促销文案, 4S店朋友圈文案, 试驾邀约话术, 车展活动文案, 置换补贴宣传文案
Regional nuance: 结合中国汽车销售常见打法，突出现金优惠、金融贴息、置换补贴、上牌礼包和区域限时政策。
Market notes: Favor mobile-first density, direct utility, trust signals, and references to common Chinese business workflows.
Template hint: 按“车型卖点—优惠政策—试驾利益—到店礼—限时收口”设计多场景文案。
Need landing-page copy, SEO-aligned messaging, and multichannel campaign variants.

Linked knowledge digest:
No linked knowledge files.

Recent memory digest:
No recent memory summaries.

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