diff --git a/SKILL.md b/SKILL.md
index 02c3dcf..bd89c67 100644
--- a/SKILL.md
+++ b/SKILL.md
@@ -1,11 +1,11 @@
 ---
 name: 1688-logistics-scraper
-description: "Scrape 1688 product pages via Chrome, capture full-page screenshots and detail images for vision-based extraction of weight/size/logistics data. Use when the user provides a 1688 product URL and needs logistics specs."
+description: "Scrape 1688 product pages via Chrome, capture full-page screenshots and detail images for vision-based extraction of weight/size data. Use when the user provides a 1688 product URL and needs logistics specs."
 ---
 
 # 1688 Logistics Scraper
 
-Capture 1688 product pages for vision-based extraction of weight, size, and logistics data.
+Capture 1688 product pages and extract weight/size data via vision.
 
 ## Run
 
@@ -13,54 +13,80 @@ Capture 1688 product pages for vision-based extraction of weight, size, and logi
 bun scripts/run.ts scrape <url> [--dry-run] [--port=9222]
 ```
 
-### Examples
-
-```bash
-bun scripts/run.ts scrape 'https://detail.1688.com/offer/852504650877.html'
-bun scripts/run.ts scrape 'https://detail.1688.com/offer/852504650877.html' --dry-run
-```
-
 ## What It Does
 
 1. Opens the 1688 product URL in the browser (default port 18800)
-2. Scrolls through the entire page, capturing **full-page screenshots** section by section
-3. Downloads all **product detail images** (large images only, skips icons)
-4. Saves everything to `/tmp/1688-logistics/<offer-id>/`
+2. Scrolls through the entire page, capturing full-page screenshots
+3. Downloads all product detail images
+4. Saves to `/tmp/1688-logistics/<offer-id>/`
 
-**No DOM parsing or regex.** The model reads the screenshots and images directly to extract logistics data.
+## After Running — MUST follow
 
-## Output
+Read ALL screenshots and detail images, then output the following JSON structure. This is the final output for API consumption.
 
 ```json
 {
-  "status": "success",
-  "url": "https://detail.1688.com/offer/...",
-  "offerId": "852504650877",
-  "screenshots": [
-    "/tmp/1688-logistics/852504650877/screenshots/page_001.png",
-    "/tmp/1688-logistics/852504650877/screenshots/page_002.png",
-    "/tmp/1688-logistics/852504650877/screenshots/page_003.png"
-  ],
-  "detailImages": [
-    "/tmp/1688-logistics/852504650877/images/img_001.jpg",
-    "/tmp/1688-logistics/852504650877/images/img_002.jpg"
+  "offerId": "966107271425",
+  "url": "https://detail.1688.com/offer/966107271425.html",
+  "title": "商品标题",
+  "weight": {
+    "value": 0.15,
+    "unit": "kg",
+    "source": "商品属性"
+  },
+  "grossWeight": {
+    "value": 0.2,
+    "unit": "kg",
+    "source": "商品件重尺"
+  },
+  "netWeight": {
+    "value": 0.15,
+    "unit": "kg",
+    "source": "商品属性"
+  },
+  "dimensions": {
+    "length": 10,
+    "width": 8,
+    "height": 1.8,
+    "unit": "cm",
+    "source": "商品属性"
+  },
+  "volume": {
+    "value": 0.000144,
+    "unit": "m³",
+    "source": "商品件重尺"
+  },
+  "packageWeight": {
+    "value": 5.0,
+    "unit": "kg",
+    "source": "包装信息"
+  },
+  "packageDimensions": {
+    "length": 40,
+    "width": 30,
+    "height": 20,
+    "unit": "cm",
+    "source": "包装信息"
+  },
+  "unitsPerPackage": 50,
+  "variants": [
+    {
+      "name": "12支装",
+      "weight": { "value": 0.12, "unit": "kg" },
+      "dimensions": { "length": 9.5, "width": 6, "height": 2.2, "unit": "cm" }
+    }
   ]
 }
 ```
 
-## After Running
+### Field rules
 
-Read the screenshots and images to extract:
-
-- **Weight** (重量/毛重/净重/单件重量) — normalize to kg
-- **Dimensions** (尺寸/长宽高) — normalize to cm
-- **Volume** (体积/容积)
-- **Package info** (包装信息) — packaging type, box weight, box dimensions, units per box
-- **Piece weight/size** (商品件重尺) — per-piece logistics specs
-- **Variant-specific** weight/size if shown per SKU
-- **Shipping info** — method, cost, origin
-
-Output the extracted data as structured JSON.
+- **All weight values normalized to kg** (克÷1000, 斤×0.5)
+- **All dimension values normalized to cm** (mm÷10)
+- **`source`**: where on the page the data was found (商品属性 / 商品件重尺 / 包装信息 / 详情图片)
+- **`variants`**: only include if weight/size differs per SKU. Omit if all variants share the same specs.
+- **Omit fields that are `null`** — do not include fields where no data was found
+- **Do not guess.** Only include values actually visible on the page or in images.
 
 ## Rules
 
@@ -68,3 +94,4 @@ Output the extracted data as structured JSON.
 2. No retries. If it fails, report as-is.
 3. Read ALL screenshots — logistics data can appear anywhere on the page.
 4. Read detail images too — weight/size is often baked into product photos.
+5. Output ONLY the structured JSON above. No extra commentary.