Update README with complete English documentation

Author: hbjkl

README.md

@@ -1,18 +1,16 @@
-# BakeCost Studio (暖木工坊 · 配方成本与定价核算器)
+# BakeCost Studio (Bakery & Recipe Cost Calculator)
 
-专为海外独立烘焙师、家庭私房甜品作坊 (Cottage Bakery) 与小型 Café 设计的纯前端单页成本核算与智能定价工具。
+A professional, privacy-first, client-side recipe costing and food pricing calculator designed for international independent bakers, home cottage bakeries, and small café owners.
 
-## 🌟 核心特性
-1. **100% 浏览器本地存储 (Local Storage)**：所有配方商业机密绝不上云，保护独立烘焙师配方隐私。
-2. **40+ 常见烘焙原料容重/密度自动换算**：支持按重量 (g/kg/oz/lb) 或体积 (Cup/勺) 自动折算进货包装单价。
-3. **损耗与烤损率 (Yield % & Baking Loss)**：精准计入去皮去蒂损耗与整炉烘烤水分蒸发。
-4. **三段式成本分摊**：食材原料 + 包装耗材 + 人工工时 + 水电固定开销分摊。
-5. **实时双向定价联动**：拖动目标 Food Cost % 滑块即时给出建议售价，或输入期望售价反推实际毛利与净利润。
-6. **一键生成高规格报价单**：支持一键导出高清成本卡图片 (PNG) 或调用系统打印存为 PDF。
-7. **数据冷备份与恢复**：支持一键导出/导入完整配方 JSON。
+## 🌟 Key Features
+1. **100% Client-Side Privacy (Local Storage)**: All proprietary recipes and cost numbers remain strictly on your local device.
+2. **40+ Built-in Baking Ingredient Densities**: Instant auto-conversion between Weight (g/kg/oz/lb) and Volume (Cup/Tbsp/Tsp/ml) based on standard culinary density tables.
+3. **Baking Loss & Yield / Trim Rates**: Accurate accounting for peeling/trimming prep loss and oven moisture evaporation.
+4. **Three-Tier Cost Allocation**: Ingredients + Packaging Supplies + Labor Time + Kitchen Electricity/Overhead.
+5. **Two-Way Real-time Pricing Engine**: Slide the Target Food Cost % (15% ~ 50%) to compute suggested price, or type a custom retail price to evaluate net profit and gross margin %.
+6. **Printable Recipe Cards & PNG Export**: One-click high-resolution PNG image download or PDF print sheet.
+7. **Offline PWA Support**: Installable on iOS/Android home screens and fully functional offline.
+8. **Data Backup & Restore**: Export and import full recipe data in JSON format.
 
-## 🚀 部署上线指引 (Cloudflare Pages)
-1. 登录 Cloudflare Dashboard -> 进入 Workers & Pages;
-2. 选择 Create application -> Pages -> Upload assets;
-3. 将当前 outputs 文件夹直接拖拽上传;
-4. 点击 Deploy 即可获得免费极速的 global CDN 线上站点!
+## 🚀 Live Demo
+- **URL**: [https://ismilewolf-eng.github.io/bakecost-studio/](https://ismilewolf-eng.github.io/bakecost-studio/)