diff --git a/.agent/rules/framework.md b/.agent/rules/framework.md
index a3e5419..0b57d23 100644
--- a/.agent/rules/framework.md
+++ b/.agent/rules/framework.md
@@ -5,73 +5,64 @@ trigger: always_on
 ---
 trigger: always_on
 ---
-預設專案運行於 WSL2 的 Laravel Sail (Docker) 環境。
-開發框架規範說明書：ERP 系統 (koori-erp)
-1. 專案概述
-目標： 打造一個強大且穩定的 ERP 後台管理系統。
 
-核心架構： 採用 單體式架構配現代化前端 (Monolith with a Modern Frontend)。使用 Laravel、Inertia.js 及 React。
+# 開發框架規範說明書：ERP 系統 (star-erp)
 
-工作流程： 將 UI/UX 設計師提供的 React 原始碼，透過 Inertia.js 整合進 Laravel 環境中。
+## 1. 專案概述
+*   **目標**： 打造一個強大且穩定的 ERP 後台管理系統。
+*   **核心架構**： 採用 **模組化單體式架構 (Modular Monolith)** 配現代化前端。使用 Laravel、Inertia.js 及 React。
+*   **工作流程**： 將 UI/UX 設計師提供的 React 原始碼，透過 Inertia.js 整合進 Laravel 環境中。後端邏輯依據「業務領域」拆分為獨立模組。
 
-2. 技術棧 (Tech Stack)
-後端： PHP 8.5 / Laravel 12
+## 2. 技術棧 (Tech Stack)
+*   **後端**： PHP 8.5 / Laravel 12
+*   **前端橋樑**： Inertia.js (不使用傳統 RESTful API 串接頁面，改用 Inertia 協議)
+*   **前端庫**： React (以 Functional Components 與 Hooks 為主)
+*   **樣式處理**： Tailwind CSS (確保與 UI/UX 設計稿完全一致)
+*   **資料庫**： MySQL 8.0
+*   **開發環境**： Laravel Sail (Docker / WSL2)
+*   **未來擴充**： 針對高併發或跨平台模組，預留 Golang 微服務接口。
 
-前端橋樑： Inertia.js (不使用傳統 RESTful API 串接頁面，改用 Inertia 協議)
+## 3. 目錄結構與慣例
 
-前端庫： React (以 Functional Components 與 Hooks 為主)
+### 3.1 後端 (Laravel - Modular Monolith)
+系統採用模組化架構，核心邏輯位於 `app/Modules/` 下：
 
-樣式處理： Tailwind CSS (確保與 UI/UX 設計稿完全一致)
+*   **Modules**： 位於 `app/Modules/{ModuleName}/`。
+    *   **Controllers**： `app/Modules/{ModuleName}/Controllers/`。必須回傳 `Inertia::render()`。
+    *   **Models**： `app/Modules/{ModuleName}/Models/`。
+    *   **Routes**： `app/Modules/{ModuleName}/Routes/web.php`。各模組獨立管理路由。
+*   **Global Routes**： `routes/web.php` 僅保留全域通用路由或作為模組路由的載入點。
 
-資料庫： MySQL 8.0
+### 3.2 前端 (React)
+*   **Pages (頁面)**： 位於 `resources/js/Pages/`。每個檔案代表一個完整的路由視圖。
+*   **Components (組件)**： 位於 `resources/js/Components/`。存放由 UI/UX 團隊提供的可重複使用 UI 元件。
+*   **Layouts (版面)**： 位於 `resources/js/Layouts/`。定義 ERP 的通用版面。
 
-開發環境： Laravel Sail (Docker / WSL2)
+## 4. 整合指南 (UI/UX 轉換至 Laravel)
+*   **組件遷移**： 將 UI/UX 的 React 原始碼移入 `resources/js/` 時，應進行「原子化」拆解，提高元件複用率。
+*   **資料傳遞**： 透過 Laravel Controller 的 props 傳送動態資料給 React。優先使用 Inertia 資料流，避免初次渲染時使用 axios。
+*   **狀態管理**： 優先使用 Inertia 內建的狀態管理與 useForm hook 處理表單提交。
 
-未來擴充： 針對高併發或跨平台模組，預留 Golang 微服務接口。
+## 5. 開發標準 (Coding Standards)
+*   **命名規範**：
+    *   Controllers: `PascalCaseController.php`
+    *   React Components: `PascalCase.jsx`
+    *   Routes: `kebab-case` (小寫橫線分隔)
+*   **回傳格式**： 所有的前後端溝通需維持一致的 JSON 結構，特別是驗證錯誤 (Validation Errors) 與閃存訊息 (Flash Messages)。
 
-3. 目錄結構與慣例
-3.1 後端 (Laravel)
-Controllers： 必須回傳 Inertia::render() 來渲染頁面。
+## 6. AI 協作規則 (給 Antigravity AI)
+*   **角色設定**： 你是一位專業的全端開發工程師助手。
+*   **代碼生成指令**：
+    *   所有的解釋說明請使用 **繁體中文**。
+    *   生成 React 組件時，必須符合專案現有的 Tailwind CSS 配置。
+    *   必須考慮 ERP 邏輯（例如：權限判斷、操作日誌、資料完整性）。
+    *   新增功能時，請先判斷應歸屬於哪個 Module，並建立在 `app/Modules/` 對應目錄下。
 
-Models： 嚴格執行型別標註，使用 Eloquent 進行資料庫操作。
+## 7. 運行機制 (Docker / Sail)
+由於專案運行在 Docker 容器環境中，請勿直接在宿主機 (Host) 執行 php 或 composer 指令。請使用專案內建的 `sail` 指令：
 
-Routes： 統一在 routes/web.php 定義 Inertia 路由。
-
-3.2 前端 (React)
-Pages (頁面)： 位於 resources/js/Pages/。每個檔案代表一個完整的路由視圖。
-
-Components (組件)： 位於 resources/js/Components/。存放由 UI/UX 團隊提供的可重複使用 UI 元件。
-
-Layouts (版面)： 位於 resources/js/Layouts/。定義 ERP 的通用版面（例如：包含側邊欄 Sidebar 與導覽列 Navbar 的後台主框架）。
-
-4. 整合指南 (UI/UX 轉換至 Laravel)
-組件遷移： 將 UI/UX 的 React 原始碼移入 resources/js/ 時，應進行「原子化」拆解，提高元件複用率。
-
-資料傳遞： 透過 Laravel Controller 的 props 傳送動態資料給 React。除非是後續的異步請求，否則避免在 React 初次渲染時使用 axios 抓取資料，應優先使用 Inertia 的資料流。
-
-狀態管理： 優先使用 Inertia 內建的狀態管理與 useForm hook 處理表單提交。
-
-5. 開發標準 (Coding Standards)
-命名規範：
-
-Controllers: PascalCaseController.php
-
-React Components: PascalCase.jsx
-
-Routes: kebab-case (小寫橫線分隔)
-
-回傳格式： 所有的前後端溝通需維持一致的 JSON 結構，特別是驗證錯誤 (Validation Errors) 與閃存訊息 (Flash Messages)。
-
-6. AI 協作規則 (給 Antigravity AI)
-角色設定： 你是一位專業的全端開發工程師助手。
-
-代碼生成指令：
-
-所有的解釋說明請使用 繁體中文。
-
-生成 React 組件時，必須符合專案現有的 Tailwind CSS 配置。
-
-必須考慮 ERP 邏輯（例如：權限判斷、操作日誌、資料完整性）。
-
-7.運行機制 
-因為是運行在docker上 所以要執行php的話 要執行docker exce
\ No newline at end of file
+*   **啟動環境**： `./vendor/bin/sail up -d`
+*   **執行 PHP 指令**： `./vendor/bin/sail php -v`
+*   **執行 Artisan 指令**： `./vendor/bin/sail artisan route:list`
+*   **執行 Composer**： `./vendor/bin/sail composer install`
+*   **執行 Node/NPM**： `./vendor/bin/sail npm run dev`
\ No newline at end of file
diff --git a/.agent/skills/activity-logging/SKILL.md b/.agent/skills/activity-logging/SKILL.md
index f8ec3ec..854df5a 100644
--- a/.agent/skills/activity-logging/SKILL.md
+++ b/.agent/skills/activity-logging/SKILL.md
@@ -101,8 +101,8 @@ public function tapActivity(\Spatie\Activitylog\Contracts\Activity $activity, st
 protected function getSubjectMap()
 {
     return [
-        'App\Models\Product' => '商品',
-        'App\Models\UtilityFee' => '公共事業費', // ✅ 新增映射
+        'App\Modules\Inventory\Models\Product' => '商品',
+        'App\Modules\Finance\Models\UtilityFee' => '公共事業費', // ✅ 新增映射
     ];
 }
 ```
diff --git a/app/Console/Commands/MigrateToTenant.php b/app/Console/Commands/MigrateToTenant.php
index 0f1f0fd..609b710 100644
--- a/app/Console/Commands/MigrateToTenant.php
+++ b/app/Console/Commands/MigrateToTenant.php
@@ -2,7 +2,7 @@
 
 namespace App\Console\Commands;
 
-use App\Models\Tenant;
+use App\Modules\Core\Models\Tenant;
 use Illuminate\Console\Command;
 use Illuminate\Support\Facades\DB;
 use Illuminate\Support\Facades\Schema;
diff --git a/app/Http/Controllers/Landlord/DashboardController.php b/app/Http/Controllers/Landlord/DashboardController.php
index 82680d1..e7759cc 100644
--- a/app/Http/Controllers/Landlord/DashboardController.php
+++ b/app/Http/Controllers/Landlord/DashboardController.php
@@ -3,7 +3,7 @@
 namespace App\Http\Controllers\Landlord;
 
 use App\Http\Controllers\Controller;
-use App\Models\Tenant;
+use App\Modules\Core\Models\Tenant;
 use Inertia\Inertia;
 
 class DashboardController extends Controller
diff --git a/app/Http/Controllers/Landlord/TenantController.php b/app/Http/Controllers/Landlord/TenantController.php
index 2e980b7..2f67647 100644
--- a/app/Http/Controllers/Landlord/TenantController.php
+++ b/app/Http/Controllers/Landlord/TenantController.php
@@ -3,7 +3,7 @@
 namespace App\Http\Controllers\Landlord;
 
 use App\Http\Controllers\Controller;
-use App\Models\Tenant;
+use App\Modules\Core\Models\Tenant;
 use Illuminate\Http\Request;
 use Illuminate\Validation\Rule;
 use Inertia\Inertia;
diff --git a/app/Models/ProductionOrder.php b/app/Models/ProductionOrder.php
deleted file mode 100644
index 81642a3..0000000
--- a/app/Models/ProductionOrder.php
+++ /dev/null
@@ -1,120 +0,0 @@
-<?php
-
-namespace App\Models;
-
-use Illuminate\Database\Eloquent\Factories\HasFactory;
-use Illuminate\Database\Eloquent\Model;
-use Illuminate\Database\Eloquent\Relations\BelongsTo;
-use Illuminate\Database\Eloquent\Relations\HasMany;
-use Spatie\Activitylog\Traits\LogsActivity;
-use Spatie\Activitylog\LogOptions;
-
-class ProductionOrder extends Model
-{
-    use HasFactory, LogsActivity;
-
-    protected $fillable = [
-        'code',
-        'product_id',
-        'output_batch_number',
-        'output_box_count',
-        'output_quantity',
-        'warehouse_id',
-        'production_date',
-        'expiry_date',
-        'user_id',
-        'status',
-        'remark',
-    ];
-
-    protected $casts = [
-        'production_date' => 'date:Y-m-d',
-        'expiry_date' => 'date:Y-m-d',
-        'output_quantity' => 'decimal:2',
-    ];
-
-    /**
-     * 成品商品
-     */
-    public function product(): BelongsTo
-    {
-        return $this->belongsTo(Product::class);
-    }
-
-    /**
-     * 入庫倉庫
-     */
-    public function warehouse(): BelongsTo
-    {
-        return $this->belongsTo(Warehouse::class);
-    }
-
-    /**
-     * 操作人員
-     */
-    public function user(): BelongsTo
-    {
-        return $this->belongsTo(User::class);
-    }
-
-    /**
-     * 生產工單明細 (BOM)
-     */
-    public function items(): HasMany
-    {
-        return $this->hasMany(ProductionOrderItem::class);
-    }
-
-    /**
-     * 活動日誌設定
-     */
-    public function getActivitylogOptions(): LogOptions
-    {
-        return LogOptions::defaults()
-            ->logAll()
-            ->logOnlyDirty()
-            ->dontSubmitEmptyLogs();
-    }
-
-    /**
-     * 活動日誌快照
-     */
-    public function tapActivity(\Spatie\Activitylog\Contracts\Activity $activity, string $eventName)
-    {
-        $properties = $activity->properties;
-        $attributes = $properties['attributes'] ?? [];
-        $snapshot = $properties['snapshot'] ?? [];
-
-        // 快照關鍵名稱
-        $snapshot['production_code'] = $this->code;
-        $snapshot['product_name'] = $this->product ? $this->product->name : null;
-        $snapshot['warehouse_name'] = $this->warehouse ? $this->warehouse->name : null;
-        $snapshot['user_name'] = $this->user ? $this->user->name : null;
-
-        $properties['attributes'] = $attributes;
-        $properties['snapshot'] = $snapshot;
-        $activity->properties = $properties;
-    }
-
-    /**
-     * 產生生產單號
-     */
-    public static function generateCode(): string
-    {
-        $date = now()->format('Ymd');
-        $prefix = "PRO-{$date}-";
-        
-        $lastOrder = static::where('code', 'like', "{$prefix}%")
-            ->orderByDesc('code')
-            ->first();
-
-        if ($lastOrder) {
-            $lastNumber = (int) substr($lastOrder->code, -3);
-            $nextNumber = str_pad($lastNumber + 1, 3, '0', STR_PAD_LEFT);
-        } else {
-            $nextNumber = '001';
-        }
-
-        return $prefix . $nextNumber;
-    }
-}
diff --git a/app/Models/ProductionOrderItem.php b/app/Models/ProductionOrderItem.php
deleted file mode 100644
index d8cf3fe..0000000
--- a/app/Models/ProductionOrderItem.php
+++ /dev/null
@@ -1,47 +0,0 @@
-<?php
-
-namespace App\Models;
-
-use Illuminate\Database\Eloquent\Factories\HasFactory;
-use Illuminate\Database\Eloquent\Model;
-use Illuminate\Database\Eloquent\Relations\BelongsTo;
-
-class ProductionOrderItem extends Model
-{
-    use HasFactory;
-
-    protected $fillable = [
-        'production_order_id',
-        'inventory_id',
-        'quantity_used',
-        'unit_id',
-    ];
-
-    protected $casts = [
-        'quantity_used' => 'decimal:4',
-    ];
-
-    /**
-     * 所屬生產工單
-     */
-    public function productionOrder(): BelongsTo
-    {
-        return $this->belongsTo(ProductionOrder::class);
-    }
-
-    /**
-     * 使用的庫存紀錄
-     */
-    public function inventory(): BelongsTo
-    {
-        return $this->belongsTo(Inventory::class);
-    }
-
-    /**
-     * 單位
-     */
-    public function unit(): BelongsTo
-    {
-        return $this->belongsTo(Unit::class);
-    }
-}
diff --git a/app/Models/PurchaseOrder.php b/app/Models/PurchaseOrder.php
deleted file mode 100644
index 794647e..0000000
--- a/app/Models/PurchaseOrder.php
+++ /dev/null
@@ -1,166 +0,0 @@
-<?php
-
-namespace App\Models;
-
-use Illuminate\Database\Eloquent\Factories\HasFactory;
-use Illuminate\Database\Eloquent\Model;
-use Illuminate\Database\Eloquent\Relations\BelongsTo;
-use Illuminate\Database\Eloquent\Relations\HasMany;
-use Spatie\Activitylog\Traits\LogsActivity;
-use Spatie\Activitylog\LogOptions;
-
-class PurchaseOrder extends Model
-{
-    use HasFactory, LogsActivity;
-
-    protected $fillable = [
-        'code',
-        'vendor_id',
-        'warehouse_id',
-        'user_id',
-        'status',
-        'expected_delivery_date',
-        'total_amount',
-        'tax_amount',
-        'grand_total',
-        'remark',
-        'invoice_number',
-        'invoice_date',
-        'invoice_amount',
-    ];
-
-    protected $casts = [
-        'expected_delivery_date' => 'date:Y-m-d',
-        'invoice_date' => 'date:Y-m-d',
-        'total_amount' => 'decimal:2',
-        'tax_amount' => 'decimal:2',
-        'grand_total' => 'decimal:2',
-        'invoice_amount' => 'decimal:2',
-    ];
-
-    protected $appends = [
-        'poNumber',
-        'supplierId',
-        'supplierName',
-        'expectedDate',
-        'totalAmount',
-        'taxAmount', // Add this
-        'grandTotal', // Add this
-        'createdBy',
-        'warehouse_name',
-        'createdAt',
-        'invoiceNumber',
-        'invoiceDate',
-        'invoiceAmount',
-    ];
-
-    public function getCreatedAtAttribute()
-    {
-        return $this->attributes['created_at'];
-    }
-
-    public function getPoNumberAttribute(): string
-    {
-        return $this->code;
-    }
-
-    public function getSupplierIdAttribute(): string
-    {
-        return (string) $this->vendor_id;
-    }
-
-    public function getSupplierNameAttribute(): string
-    {
-        return $this->vendor ? $this->vendor->name : '';
-    }
-
-    public function getExpectedDateAttribute(): ?string
-    {
-        return $this->attributes['expected_delivery_date'] ?? null;
-    }
-
-    public function getTotalAmountAttribute(): float
-    {
-        return (float) ($this->attributes['total_amount'] ?? 0);
-    }
-
-    public function getTaxAmountAttribute(): float
-    {
-        return (float) ($this->attributes['tax_amount'] ?? 0);
-    }
-
-    public function getGrandTotalAttribute(): float
-    {
-        return (float) ($this->attributes['grand_total'] ?? 0);
-    }
-
-    public function getCreatedByAttribute(): string
-    {
-        return $this->user ? $this->user->name : '系統';
-    }
-
-    public function getWarehouseNameAttribute(): string
-    {
-        return $this->warehouse ? $this->warehouse->name : '';
-    }
-
-    public function getInvoiceNumberAttribute(): ?string
-    {
-        return $this->attributes['invoice_number'] ?? null;
-    }
-
-    public function getInvoiceDateAttribute(): ?string
-    {
-        return $this->attributes['invoice_date'] ?? null;
-    }
-
-    public function getInvoiceAmountAttribute(): ?float
-    {
-        return isset($this->attributes['invoice_amount']) ? (float) $this->attributes['invoice_amount'] : null;
-    }
-
-    public function vendor(): BelongsTo
-    {
-        return $this->belongsTo(Vendor::class);
-    }
-
-    public function warehouse(): BelongsTo
-    {
-        return $this->belongsTo(Warehouse::class);
-    }
-
-    public function user(): BelongsTo
-    {
-        return $this->belongsTo(User::class);
-    }
-
-    public function items(): HasMany
-    {
-        return $this->hasMany(PurchaseOrderItem::class);
-    }
-
-    public function getActivitylogOptions(): LogOptions
-    {
-        return LogOptions::defaults()
-            ->logAll()
-            ->logOnlyDirty()
-            ->dontSubmitEmptyLogs();
-    }
-
-    public function tapActivity(\Spatie\Activitylog\Contracts\Activity $activity, string $eventName)
-    {
-        $properties = $activity->properties;
-        $attributes = $properties['attributes'] ?? [];
-        $snapshot = $properties['snapshot'] ?? [];
-
-        // Snapshot key names
-        $snapshot['po_number'] = $this->code;
-        $snapshot['vendor_name'] = $this->vendor ? $this->vendor->name : null;
-        $snapshot['warehouse_name'] = $this->warehouse ? $this->warehouse->name : null;
-        $snapshot['user_name'] = $this->user ? $this->user->name : null;
-
-        $properties['attributes'] = $attributes;
-        $properties['snapshot'] = $snapshot;
-        $activity->properties = $properties;
-    }
-}
diff --git a/app/Models/PurchaseOrderItem.php b/app/Models/PurchaseOrderItem.php
deleted file mode 100644
index 4e8e731..0000000
--- a/app/Models/PurchaseOrderItem.php
+++ /dev/null
@@ -1,68 +0,0 @@
-<?php
-
-namespace App\Models;
-
-use Illuminate\Database\Eloquent\Factories\HasFactory;
-use Illuminate\Database\Eloquent\Model;
-use Illuminate\Database\Eloquent\Relations\BelongsTo;
-
-class PurchaseOrderItem extends Model
-{
-    use HasFactory;
-
-    protected $fillable = [
-        'purchase_order_id',
-        'product_id',
-        'quantity',
-        'unit_id', // 新增單位ID欄位
-        'unit_price',
-        'subtotal',
-        'received_quantity',
-    ];
-
-    protected $casts = [
-        'quantity' => 'decimal:2',
-        'unit_price' => 'decimal:2',
-        'subtotal' => 'decimal:2',
-        'received_quantity' => 'decimal:2',
-    ];
-
-    public function getProductNameAttribute(): string
-    {
-        return $this->product?->name ?? '';
-    }
-    
-    // 關聯單位
-    public function unit(): \Illuminate\Database\Eloquent\Relations\BelongsTo
-    {
-        return $this->belongsTo(Unit::class);
-    }
-
-    public function getUnitNameAttribute(): string
-    {
-        // 優先使用關聯的 unit
-        if ($this->unit) {
-            return $this->unit->name;
-        }
-
-        if (!$this->product) {
-            return '';
-        }
-        
-        // Fallback: 嘗試從 Product 的關聯單位獲取
-        return $this->product->purchaseUnit?->name 
-            ?? $this->product->largeUnit?->name 
-            ?? $this->product->baseUnit?->name 
-            ?? '';
-    }
-
-    public function purchaseOrder(): BelongsTo
-    {
-        return $this->belongsTo(PurchaseOrder::class);
-    }
-
-    public function product(): BelongsTo
-    {
-        return $this->belongsTo(Product::class);
-    }
-}
diff --git a/app/Models/UtilityFee.php b/app/Models/UtilityFee.php
deleted file mode 100644
index aadaefc..0000000
--- a/app/Models/UtilityFee.php
+++ /dev/null
@@ -1,24 +0,0 @@
-<?php
-
-namespace App\Models;
-
-use Illuminate\Database\Eloquent\Factories\HasFactory;
-use Illuminate\Database\Eloquent\Model;
-
-class UtilityFee extends Model
-{
-    use HasFactory;
-
-    protected $fillable = [
-        'transaction_date',
-        'category',
-        'amount',
-        'invoice_number',
-        'description',
-    ];
-
-    protected $casts = [
-        'transaction_date' => 'date:Y-m-d',
-        'amount' => 'decimal:2',
-    ];
-}
diff --git a/app/Modules/.gitkeep b/app/Modules/.gitkeep
new file mode 100644
index 0000000..e69de29
diff --git a/app/Http/Controllers/Admin/ActivityLogController.php b/app/Modules/Core/Controllers/ActivityLogController.php
similarity index 82%
rename from app/Http/Controllers/Admin/ActivityLogController.php
rename to app/Modules/Core/Controllers/ActivityLogController.php
index 0e351e0..23bd36b 100644
--- a/app/Http/Controllers/Admin/ActivityLogController.php
+++ b/app/Modules/Core/Controllers/ActivityLogController.php
@@ -1,8 +1,9 @@
 <?php
 
-namespace App\Http\Controllers\Admin;
+namespace App\Modules\Core\Controllers;
 
 use App\Http\Controllers\Controller;
+
 use Illuminate\Http\Request;
 use Inertia\Inertia;
 use Spatie\Activitylog\Models\Activity;
@@ -12,16 +13,16 @@ class ActivityLogController extends Controller
     private function getSubjectMap()
     {
         return [
-            'App\Models\User' => '使用者',
-            'App\Models\Role' => '角色',
-            'App\Models\Product' => '商品',
-            'App\Models\Vendor' => '廠商',
-            'App\Models\Category' => '商品分類',
-            'App\Models\Unit' => '單位',
-            'App\Models\PurchaseOrder' => '採購單',
-            'App\Models\Warehouse' => '倉庫',
-            'App\Models\Inventory' => '庫存',
-            'App\Models\UtilityFee' => '公共事業費',
+            'App\Modules\Core\Models\User' => '使用者',
+            'App\Modules\Core\Models\Role' => '角色',
+            'App\Modules\Inventory\Models\Product' => '商品',
+            'App\Modules\Procurement\Models\Vendor' => '廠商',
+            'App\Modules\Inventory\Models\Category' => '商品分類',
+            'App\Modules\Inventory\Models\Unit' => '單位',
+            'App\Modules\Procurement\Models\PurchaseOrder' => '採購單',
+            'App\Modules\Inventory\Models\Warehouse' => '倉庫',
+            'App\Modules\Inventory\Models\Inventory' => '庫存',
+            'App\Modules\Finance\Models\UtilityFee' => '公共事業費',
         ];
     }
 
@@ -101,7 +102,7 @@ class ActivityLogController extends Controller
         })->values();
 
         // Get users for causer filter
-        $users = \App\Models\User::select('id', 'name')->orderBy('name')->get()
+        $users = \App\Modules\Core\Models\User::select('id', 'name')->orderBy('name')->get()
             ->map(function ($user) {
                 return ['label' => $user->name, 'value' => (string) $user->id];
             });
diff --git a/app/Http/Controllers/Auth/LoginController.php b/app/Modules/Core/Controllers/Auth/LoginController.php
similarity index 97%
rename from app/Http/Controllers/Auth/LoginController.php
rename to app/Modules/Core/Controllers/Auth/LoginController.php
index a8d64f3..661fb1b 100644
--- a/app/Http/Controllers/Auth/LoginController.php
+++ b/app/Modules/Core/Controllers/Auth/LoginController.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace App\Http\Controllers\Auth;
+namespace App\Modules\Core\Controllers\Auth;
 
 use App\Http\Controllers\Controller;
 use Illuminate\Http\Request;
diff --git a/app/Http/Controllers/DashboardController.php b/app/Modules/Core/Controllers/DashboardController.php
similarity index 82%
rename from app/Http/Controllers/DashboardController.php
rename to app/Modules/Core/Controllers/DashboardController.php
index 9a21288..ec95777 100644
--- a/app/Http/Controllers/DashboardController.php
+++ b/app/Modules/Core/Controllers/DashboardController.php
@@ -1,13 +1,15 @@
 <?php
 
-namespace App\Http\Controllers;
+namespace App\Modules\Core\Controllers;
 
-use App\Models\Product;
-use App\Models\Vendor;
-use App\Models\PurchaseOrder;
-use App\Models\Warehouse;
-use App\Models\Inventory;
-use App\Models\WarehouseProductSafetyStock;
+use App\Http\Controllers\Controller;
+
+use App\Modules\Inventory\Models\Product;
+use App\Modules\Procurement\Models\Vendor;
+use App\Modules\Procurement\Models\PurchaseOrder;
+use App\Modules\Inventory\Models\Warehouse;
+use App\Modules\Inventory\Models\Inventory;
+use App\Modules\Inventory\Models\WarehouseProductSafetyStock;
 use Inertia\Inertia;
 use Illuminate\Http\Request;
 use Illuminate\Support\Facades\DB;
diff --git a/app/Http/Controllers/ProfileController.php b/app/Modules/Core/Controllers/ProfileController.php
similarity index 94%
rename from app/Http/Controllers/ProfileController.php
rename to app/Modules/Core/Controllers/ProfileController.php
index d95076d..fa6d14d 100644
--- a/app/Http/Controllers/ProfileController.php
+++ b/app/Modules/Core/Controllers/ProfileController.php
@@ -1,8 +1,9 @@
 <?php
 
-namespace App\Http\Controllers;
+namespace App\Modules\Core\Controllers;
+
+use App\Http\Controllers\Controller;
 
-use Illuminate\Http\Request;
 use Illuminate\Support\Facades\Hash;
 use Illuminate\Validation\Rules\Password;
 use Inertia\Inertia;
diff --git a/app/Http/Controllers/Admin/RoleController.php b/app/Modules/Core/Controllers/RoleController.php
similarity index 99%
rename from app/Http/Controllers/Admin/RoleController.php
rename to app/Modules/Core/Controllers/RoleController.php
index c8f378a..7e1f464 100644
--- a/app/Http/Controllers/Admin/RoleController.php
+++ b/app/Modules/Core/Controllers/RoleController.php
@@ -1,8 +1,9 @@
 <?php
 
-namespace App\Http\Controllers\Admin;
+namespace App\Modules\Core\Controllers;
 
 use App\Http\Controllers\Controller;
+
 use Illuminate\Http\Request;
 use Spatie\Permission\Models\Role;
 use Spatie\Permission\Models\Permission;
diff --git a/app/Http/Controllers/Admin/UserController.php b/app/Modules/Core/Controllers/UserController.php
similarity index 99%
rename from app/Http/Controllers/Admin/UserController.php
rename to app/Modules/Core/Controllers/UserController.php
index d646092..291ae24 100644
--- a/app/Http/Controllers/Admin/UserController.php
+++ b/app/Modules/Core/Controllers/UserController.php
@@ -1,9 +1,10 @@
 <?php
 
-namespace App\Http\Controllers\Admin;
+namespace App\Modules\Core\Controllers;
 
 use App\Http\Controllers\Controller;
-use App\Models\User;
+
+use App\Modules\Core\Models\User;
 use Illuminate\Http\Request;
 use Spatie\Permission\Models\Role;
 use Inertia\Inertia;
diff --git a/app/Models/Role.php b/app/Modules/Core/Models/Role.php
similarity index 91%
rename from app/Models/Role.php
rename to app/Modules/Core/Models/Role.php
index 4fd89e5..794ae1b 100644
--- a/app/Models/Role.php
+++ b/app/Modules/Core/Models/Role.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace App\Models;
+namespace App\Modules\Core\Models;
 
 use Spatie\Permission\Models\Role as SpatieRole;
 use Spatie\Activitylog\Traits\LogsActivity;
diff --git a/app/Models/Tenant.php b/app/Modules/Core/Models/Tenant.php
similarity index 96%
rename from app/Models/Tenant.php
rename to app/Modules/Core/Models/Tenant.php
index 09d7601..4f5e67e 100644
--- a/app/Models/Tenant.php
+++ b/app/Modules/Core/Models/Tenant.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace App\Models;
+namespace App\Modules\Core\Models;
 
 use Stancl\Tenancy\Database\Models\Tenant as BaseTenant;
 use Stancl\Tenancy\Contracts\TenantWithDatabase;
diff --git a/app/Models/User.php b/app/Modules/Core/Models/User.php
similarity index 97%
rename from app/Models/User.php
rename to app/Modules/Core/Models/User.php
index 61092bc..2d96d1f 100644
--- a/app/Models/User.php
+++ b/app/Modules/Core/Models/User.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace App\Models;
+namespace App\Modules\Core\Models;
 
 // use Illuminate\Contracts\Auth\MustVerifyEmail;
 use Illuminate\Database\Eloquent\Factories\HasFactory;
diff --git a/app/Modules/Core/Routes/web.php b/app/Modules/Core/Routes/web.php
new file mode 100644
index 0000000..183a538
--- /dev/null
+++ b/app/Modules/Core/Routes/web.php
@@ -0,0 +1,54 @@
+<?php
+
+use Illuminate\Support\Facades\Route;
+use App\Modules\Core\Controllers\Auth\LoginController;
+use App\Modules\Core\Controllers\DashboardController;
+use App\Modules\Core\Controllers\ProfileController;
+use App\Modules\Core\Controllers\RoleController;
+use App\Modules\Core\Controllers\UserController;
+use App\Modules\Core\Controllers\ActivityLogController;
+
+// 登入/登出路由
+Route::get('/login', [LoginController::class, 'show'])->name('login');
+Route::post('/login', [LoginController::class, 'store']);
+Route::post('/logout', [LoginController::class, 'destroy'])->name('logout');
+
+Route::middleware('auth')->group(function () {
+    // 儀表板 - 所有登入使用者皆可存取
+    Route::get('/', [DashboardController::class, 'index'])->name('dashboard');
+
+    // 使用者帳號設定
+    Route::get('/profile', [ProfileController::class, 'edit'])->name('profile.edit');
+    Route::patch('/profile', [ProfileController::class, 'update'])->name('profile.update');
+    Route::put('/profile/password', [ProfileController::class, 'updatePassword'])->name('profile.password');
+
+    // 系統管理
+    Route::prefix('admin')->group(function () {
+        Route::middleware('permission:roles.view')->group(function () {
+            Route::get('/roles', [RoleController::class, 'index'])->name('roles.index');
+            Route::middleware('permission:roles.create')->group(function () {
+                Route::get('/roles/create', [RoleController::class, 'create'])->name('roles.create');
+                Route::post('/roles', [RoleController::class, 'store'])->name('roles.store');
+            });
+            Route::get('/roles/{role}/edit', [RoleController::class, 'edit'])->middleware('permission:roles.edit')->name('roles.edit');
+            Route::put('/roles/{role}', [RoleController::class, 'update'])->middleware('permission:roles.edit')->name('roles.update');
+            Route::delete('/roles/{role}', [RoleController::class, 'destroy'])->middleware('permission:roles.delete')->name('roles.destroy');
+        });
+        
+        Route::middleware('permission:users.view')->group(function () {
+            Route::get('/users', [UserController::class, 'index'])->name('users.index');
+            Route::middleware('permission:users.create')->group(function () {
+                Route::get('/users/create', [UserController::class, 'create'])->name('users.create');
+                Route::post('/users', [UserController::class, 'store'])->name('users.store');
+            });
+            Route::get('/users/{user}/edit', [UserController::class, 'edit'])->middleware('permission:users.edit')->name('users.edit');
+            Route::put('/users/{user}', [UserController::class, 'update'])->middleware('permission:users.edit')->name('users.update');
+            Route::delete('/users/{user}', [UserController::class, 'destroy'])->middleware('permission:users.delete')->name('users.destroy');
+        });
+
+        Route::middleware('permission:system.view_logs')->group(function () {
+            Route::get('/activity-logs', [ActivityLogController::class, 'index'])->name('activity-logs.index');
+        });
+
+    });
+});
diff --git a/app/Http/Controllers/AccountingReportController.php b/app/Modules/Finance/Controllers/AccountingReportController.php
similarity index 97%
rename from app/Http/Controllers/AccountingReportController.php
rename to app/Modules/Finance/Controllers/AccountingReportController.php
index c65dfe6..9ceb9e7 100644
--- a/app/Http/Controllers/AccountingReportController.php
+++ b/app/Modules/Finance/Controllers/AccountingReportController.php
@@ -1,9 +1,11 @@
 <?php
 
-namespace App\Http\Controllers;
+namespace App\Modules\Finance\Controllers;
 
-use App\Models\PurchaseOrder;
-use App\Models\UtilityFee;
+use App\Http\Controllers\Controller;
+
+use App\Modules\Finance\Models\UtilityFee;
+use App\Modules\Procurement\Models\PurchaseOrder;
 use Illuminate\Http\Request;
 use Inertia\Inertia;
 use Illuminate\Support\Carbon;
diff --git a/app/Http/Controllers/UtilityFeeController.php b/app/Modules/Finance/Controllers/UtilityFeeController.php
similarity index 97%
rename from app/Http/Controllers/UtilityFeeController.php
rename to app/Modules/Finance/Controllers/UtilityFeeController.php
index cf43673..057b908 100644
--- a/app/Http/Controllers/UtilityFeeController.php
+++ b/app/Modules/Finance/Controllers/UtilityFeeController.php
@@ -1,8 +1,10 @@
 <?php
 
-namespace App\Http\Controllers;
+namespace App\Modules\Finance\Controllers;
+
+use App\Http\Controllers\Controller;
+use App\Modules\Finance\Models\UtilityFee;
 
-use App\Models\UtilityFee;
 use Illuminate\Http\Request;
 use Inertia\Inertia;
 
diff --git a/app/Modules/Finance/Models/UtilityFee.php b/app/Modules/Finance/Models/UtilityFee.php
new file mode 100644
index 0000000..db9fbca
--- /dev/null
+++ b/app/Modules/Finance/Models/UtilityFee.php
@@ -0,0 +1,36 @@
+<?php
+
+namespace App\Modules\Finance\Models;
+
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+
+class UtilityFee extends Model
+{
+    /** @use HasFactory<\Database\Factories\UtilityFeeFactory> */
+    use HasFactory;
+
+    protected $fillable = [
+        'type', // 'electricity', 'water', 'gas', etc.
+        'billing_period_start',
+        'billing_period_end',
+        'due_date',
+        'amount',
+        'usage_amount', // kWh, m3, etc.
+        'unit', // 度, 立方米
+        'status', // 'pending', 'paid', 'overdue'
+        'paid_at',
+        'payment_method',
+        'notes',
+        'receipt_image_path',
+    ];
+
+    protected $casts = [
+        'billing_period_start' => 'date',
+        'billing_period_end' => 'date',
+        'due_date' => 'date',
+        'paid_at' => 'datetime',
+        'amount' => 'decimal:2',
+        'usage_amount' => 'decimal:2',
+    ];
+}
diff --git a/app/Modules/Finance/Routes/web.php b/app/Modules/Finance/Routes/web.php
new file mode 100644
index 0000000..9cb8cfe
--- /dev/null
+++ b/app/Modules/Finance/Routes/web.php
@@ -0,0 +1,29 @@
+<?php
+
+use Illuminate\Support\Facades\Route;
+use App\Modules\Finance\Controllers\UtilityFeeController;
+use App\Modules\Finance\Controllers\AccountingReportController;
+
+Route::middleware('auth')->group(function () {
+    // 公共事業費管理
+    Route::middleware('permission:utility_fees.view')->group(function () {
+        Route::get('/utility-fees', [UtilityFeeController::class, 'index'])->name('utility-fees.index');
+    });
+    Route::middleware('permission:utility_fees.create')->group(function () {
+        Route::post('/utility-fees', [UtilityFeeController::class, 'store'])->name('utility-fees.store');
+    });
+    Route::middleware('permission:utility_fees.edit')->group(function () {
+        Route::put('/utility-fees/{utility_fee}', [UtilityFeeController::class, 'update'])->name('utility-fees.update');
+    });
+    Route::middleware('permission:utility_fees.delete')->group(function () {
+        Route::delete('/utility-fees/{utility_fee}', [UtilityFeeController::class, 'destroy'])->name('utility-fees.destroy');
+    });
+
+    // 會計報表
+    Route::middleware('permission:accounting.view')->prefix('accounting-report')->group(function () {
+        Route::get('/', [AccountingReportController::class, 'index'])->name('accounting.report');
+        Route::get('/export', [AccountingReportController::class, 'export'])
+            ->middleware('permission:accounting.export')
+            ->name('accounting.export');
+    });
+});
diff --git a/app/Http/Controllers/CategoryController.php b/app/Modules/Inventory/Controllers/CategoryController.php
similarity index 91%
rename from app/Http/Controllers/CategoryController.php
rename to app/Modules/Inventory/Controllers/CategoryController.php
index ee4dd3e..8eebcee 100644
--- a/app/Http/Controllers/CategoryController.php
+++ b/app/Modules/Inventory/Controllers/CategoryController.php
@@ -1,8 +1,10 @@
 <?php
 
-namespace App\Http\Controllers;
+namespace App\Modules\Inventory\Controllers;
 
-use App\Models\Category;
+use App\Http\Controllers\Controller;
+
+use App\Modules\Inventory\Models\Category;
 use Illuminate\Http\Request;
 
 class CategoryController extends Controller
diff --git a/app/Http/Controllers/InventoryController.php b/app/Modules/Inventory/Controllers/InventoryController.php
similarity index 91%
rename from app/Http/Controllers/InventoryController.php
rename to app/Modules/Inventory/Controllers/InventoryController.php
index 61c1381..f524573 100644
--- a/app/Http/Controllers/InventoryController.php
+++ b/app/Modules/Inventory/Controllers/InventoryController.php
@@ -1,13 +1,15 @@
 <?php
 
-namespace App\Http\Controllers;
+namespace App\Modules\Inventory\Controllers;
+
+use App\Http\Controllers\Controller;
 
 use Illuminate\Http\Request;
-use App\Models\WarehouseProductSafetyStock;
+use App\Modules\Inventory\Models\WarehouseProductSafetyStock;
 
 class InventoryController extends Controller
 {
-    public function index(\Illuminate\Http\Request $request, \App\Models\Warehouse $warehouse)
+    public function index(\Illuminate\Http\Request $request, \App\Modules\Inventory\Models\Warehouse $warehouse)
     {
         $warehouse->load([
             'inventories.product.category',
@@ -15,7 +17,7 @@ class InventoryController extends Controller
             'inventories.lastIncomingTransaction',
             'inventories.lastOutgoingTransaction'
         ]);
-        $allProducts = \App\Models\Product::with('category')->get();
+        $allProducts = \App\Modules\Inventory\Models\Product::with('category')->get();
 
         // 1. 準備 availableProducts
         $availableProducts = $allProducts->map(function ($product) {
@@ -104,10 +106,10 @@ class InventoryController extends Controller
         ]);
     }
 
-    public function create(\App\Models\Warehouse $warehouse)
+    public function create(\App\Modules\Inventory\Models\Warehouse $warehouse)
     {
         // 取得所有商品供前端選單使用
-        $products = \App\Models\Product::with(['baseUnit', 'largeUnit'])
+        $products = \App\Modules\Inventory\Models\Product::with(['baseUnit', 'largeUnit'])
             ->select('id', 'name', 'code', 'base_unit_id', 'large_unit_id', 'conversion_rate')
             ->get()
             ->map(function ($product) {
@@ -127,7 +129,7 @@ class InventoryController extends Controller
         ]);
     }
 
-    public function store(\Illuminate\Http\Request $request, \App\Models\Warehouse $warehouse)
+    public function store(\Illuminate\Http\Request $request, \App\Modules\Inventory\Models\Warehouse $warehouse)
     {
         $validated = $request->validate([
             'inboundDate' => 'required|date',
@@ -148,16 +150,16 @@ class InventoryController extends Controller
 
                 if ($item['batchMode'] === 'existing') {
                     // 模式 A：選擇現有批號 (包含已刪除的也要能找回來累加)
-                    $inventory = \App\Models\Inventory::withTrashed()->findOrFail($item['inventoryId']);
+                    $inventory = \App\Modules\Inventory\Models\Inventory::withTrashed()->findOrFail($item['inventoryId']);
                     if ($inventory->trashed()) {
                         $inventory->restore();
                     }
                 } else {
                     // 模式 B：建立新批號
                     $originCountry = $item['originCountry'] ?? 'TW';
-                    $product = \App\Models\Product::find($item['productId']);
+                    $product = \App\Modules\Inventory\Models\Product::find($item['productId']);
                     
-                    $batchNumber = \App\Models\Inventory::generateBatchNumber(
+                    $batchNumber = \App\Modules\Inventory\Models\Inventory::generateBatchNumber(
                         $product->code ?? 'UNK',
                         $originCountry,
                         $validated['inboundDate']
@@ -208,12 +210,12 @@ class InventoryController extends Controller
     /**
      * API: 取得商品在特定倉庫的所有批號，並回傳當前日期/產地下的一個流水號
      */
-    public function getBatches(\App\Models\Warehouse $warehouse, $productId, \Illuminate\Http\Request $request)
+    public function getBatches(\App\Modules\Inventory\Models\Warehouse $warehouse, $productId, \Illuminate\Http\Request $request)
     {
         $originCountry = $request->query('originCountry', 'TW');
         $arrivalDate = $request->query('arrivalDate', now()->format('Y-m-d'));
 
-        $batches = \App\Models\Inventory::where('warehouse_id', $warehouse->id)
+        $batches = \App\Modules\Inventory\Models\Inventory::where('warehouse_id', $warehouse->id)
             ->where('product_id', $productId)
             ->get()
             ->map(function ($inventory) {
@@ -227,10 +229,10 @@ class InventoryController extends Controller
             });
 
         // 計算下一個流水號
-        $product = \App\Models\Product::find($productId);
+        $product = \App\Modules\Inventory\Models\Product::find($productId);
         $nextSequence = '01';
         if ($product) {
-            $batchNumber = \App\Models\Inventory::generateBatchNumber(
+            $batchNumber = \App\Modules\Inventory\Models\Inventory::generateBatchNumber(
                 $product->code ?? 'UNK',
                 $originCountry,
                 $arrivalDate
@@ -244,7 +246,7 @@ class InventoryController extends Controller
         ]);
     }
 
-    public function edit(\Illuminate\Http\Request $request, \App\Models\Warehouse $warehouse, $inventoryId)
+    public function edit(\Illuminate\Http\Request $request, \App\Modules\Inventory\Models\Warehouse $warehouse, $inventoryId)
     {
         // 取得庫存紀錄，包含商品資訊與異動紀錄 (含經手人)
         // 這裡如果是 Mock 的 ID (mock-inv-1)，需要特殊處理
@@ -252,7 +254,7 @@ class InventoryController extends Controller
              return redirect()->back()->with('error', '無法編輯範例資料');
         }
 
-        $inventory = \App\Models\Inventory::with(['product', 'transactions' => function($query) {
+        $inventory = \App\Modules\Inventory\Models\Inventory::with(['product', 'transactions' => function($query) {
             $query->orderBy('actual_time', 'desc')->orderBy('id', 'desc');
         }, 'transactions.user'])->findOrFail($inventoryId);
 
@@ -289,13 +291,13 @@ class InventoryController extends Controller
         ]);
     }
 
-    public function update(\Illuminate\Http\Request $request, \App\Models\Warehouse $warehouse, $inventoryId)
+    public function update(\Illuminate\Http\Request $request, \App\Modules\Inventory\Models\Warehouse $warehouse, $inventoryId)
     {
         // 若是 product ID (舊邏輯)，先轉為 inventory
         // 但新路由我們傳的是 inventory ID
         // 為了相容，我們先判斷 $inventoryId 是 inventory ID
         
-        $inventory = \App\Models\Inventory::find($inventoryId);
+        $inventory = \App\Modules\Inventory\Models\Inventory::find($inventoryId);
         
         // 如果找不到 (可能是舊路由傳 product ID)
         if (!$inventory) {
@@ -393,9 +395,9 @@ class InventoryController extends Controller
         });
     }
 
-    public function destroy(\App\Models\Warehouse $warehouse, $inventoryId)
+    public function destroy(\App\Modules\Inventory\Models\Warehouse $warehouse, $inventoryId)
     {
-         $inventory = \App\Models\Inventory::findOrFail($inventoryId);
+         $inventory = \App\Modules\Inventory\Models\Inventory::findOrFail($inventoryId);
          
          // 庫存 > 0 不允許刪除 (哪怕是軟刪除)
          if ($inventory->quantity > 0) {
@@ -421,14 +423,14 @@ class InventoryController extends Controller
                 ->with('success', '庫存品項已刪除');
     }
 
-    public function history(Request $request, \App\Models\Warehouse $warehouse)
+    public function history(Request $request, \App\Modules\Inventory\Models\Warehouse $warehouse)
     {
         $inventoryId = $request->query('inventoryId');
         $productId = $request->query('productId');
 
         if ($productId) {
             // 商品層級查詢
-            $inventories = \App\Models\Inventory::where('warehouse_id', $warehouse->id)
+            $inventories = \App\Modules\Inventory\Models\Inventory::where('warehouse_id', $warehouse->id)
                 ->where('product_id', $productId)
                 ->with(['product', 'transactions' => function($query) {
                     $query->orderBy('actual_time', 'desc')->orderBy('id', 'desc');
@@ -503,7 +505,7 @@ class InventoryController extends Controller
 
         if ($inventoryId) {
             // 單一批號查詢
-            $inventory = \App\Models\Inventory::with(['product', 'transactions' => function($query) {
+            $inventory = \App\Modules\Inventory\Models\Inventory::with(['product', 'transactions' => function($query) {
                 $query->orderBy('actual_time', 'desc')->orderBy('id', 'desc');
             }, 'transactions.user'])->findOrFail($inventoryId);
 
diff --git a/app/Http/Controllers/ProductController.php b/app/Modules/Inventory/Controllers/ProductController.php
similarity index 95%
rename from app/Http/Controllers/ProductController.php
rename to app/Modules/Inventory/Controllers/ProductController.php
index 6207b4e..f8348fc 100644
--- a/app/Http/Controllers/ProductController.php
+++ b/app/Modules/Inventory/Controllers/ProductController.php
@@ -1,9 +1,11 @@
 <?php
 
-namespace App\Http\Controllers;
+namespace App\Modules\Inventory\Controllers;
 
-use App\Models\Product;
-use App\Models\Unit;
+use App\Http\Controllers\Controller;
+
+use App\Modules\Inventory\Models\Product;
+use App\Modules\Inventory\Models\Unit;
 use Illuminate\Http\Request;
 use Inertia\Inertia;
 use Inertia\Response;
@@ -59,7 +61,7 @@ class ProductController extends Controller
 
         $products = $query->paginate($perPage)->withQueryString();
 
-        $categories = \App\Models\Category::where('is_active', true)->get();
+        $categories = \App\Modules\Inventory\Models\Category::where('is_active', true)->get();
 
         return Inertia::render('Product/Index', [
             'products' => $products,
diff --git a/app/Http/Controllers/SafetyStockController.php b/app/Modules/Inventory/Controllers/SafetyStockController.php
similarity index 93%
rename from app/Http/Controllers/SafetyStockController.php
rename to app/Modules/Inventory/Controllers/SafetyStockController.php
index b0449a7..69c0168 100644
--- a/app/Http/Controllers/SafetyStockController.php
+++ b/app/Modules/Inventory/Controllers/SafetyStockController.php
@@ -1,11 +1,13 @@
 <?php
 
-namespace App\Http\Controllers;
+namespace App\Modules\Inventory\Controllers;
 
-use App\Models\Warehouse;
-use App\Models\WarehouseProductSafetyStock;
-use App\Models\Product;
-use App\Models\Inventory;
+use App\Http\Controllers\Controller;
+
+use App\Modules\Inventory\Models\Warehouse;
+use App\Modules\Inventory\Models\WarehouseProductSafetyStock;
+use App\Modules\Inventory\Models\Product;
+use App\Modules\Inventory\Models\Inventory;
 use Illuminate\Http\Request;
 use Inertia\Inertia;
 use Illuminate\Support\Facades\DB;
diff --git a/app/Http/Controllers/TransferOrderController.php b/app/Modules/Inventory/Controllers/TransferOrderController.php
similarity index 96%
rename from app/Http/Controllers/TransferOrderController.php
rename to app/Modules/Inventory/Controllers/TransferOrderController.php
index 9af0715..72c8807 100644
--- a/app/Http/Controllers/TransferOrderController.php
+++ b/app/Modules/Inventory/Controllers/TransferOrderController.php
@@ -1,9 +1,11 @@
 <?php
 
-namespace App\Http\Controllers;
+namespace App\Modules\Inventory\Controllers;
 
-use App\Models\Inventory;
-use App\Models\Warehouse;
+use App\Http\Controllers\Controller;
+
+use App\Modules\Inventory\Models\Inventory;
+use App\Modules\Inventory\Models\Warehouse;
 use Illuminate\Http\Request;
 use Illuminate\Support\Facades\DB;
 use Illuminate\Validation\ValidationException;
diff --git a/app/Http/Controllers/UnitController.php b/app/Modules/Inventory/Controllers/UnitController.php
similarity index 90%
rename from app/Http/Controllers/UnitController.php
rename to app/Modules/Inventory/Controllers/UnitController.php
index 93d6b22..e8bb38d 100644
--- a/app/Http/Controllers/UnitController.php
+++ b/app/Modules/Inventory/Controllers/UnitController.php
@@ -1,9 +1,11 @@
 <?php
 
-namespace App\Http\Controllers;
+namespace App\Modules\Inventory\Controllers;
 
-use App\Models\Unit;
-use App\Models\Product; // Import Product to check for usage
+use App\Http\Controllers\Controller;
+
+use App\Modules\Inventory\Models\Unit;
+use App\Modules\Inventory\Models\Product; // Import Product to check for usage
 use Illuminate\Http\Request;
 
 class UnitController extends Controller
diff --git a/app/Http/Controllers/WarehouseController.php b/app/Modules/Inventory/Controllers/WarehouseController.php
similarity index 95%
rename from app/Http/Controllers/WarehouseController.php
rename to app/Modules/Inventory/Controllers/WarehouseController.php
index 955b77c..dc8f99a 100644
--- a/app/Http/Controllers/WarehouseController.php
+++ b/app/Modules/Inventory/Controllers/WarehouseController.php
@@ -1,10 +1,12 @@
 <?php
 
-namespace App\Http\Controllers;
+namespace App\Modules\Inventory\Controllers;
+
+use App\Http\Controllers\Controller;
 
 use Illuminate\Http\Request;
 
-use App\Models\Warehouse;
+use App\Modules\Inventory\Models\Warehouse;
 
 use Inertia\Inertia;
 
diff --git a/app/Models/Category.php b/app/Modules/Inventory/Models/Category.php
similarity index 68%
rename from app/Models/Category.php
rename to app/Modules/Inventory/Models/Category.php
index cedbcc7..130d41f 100644
--- a/app/Models/Category.php
+++ b/app/Modules/Inventory/Models/Category.php
@@ -1,37 +1,27 @@
 <?php
 
-namespace App\Models;
+namespace App\Modules\Inventory\Models;
 
 use Illuminate\Database\Eloquent\Factories\HasFactory;
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\Relations\HasMany;
 use Spatie\Activitylog\Traits\LogsActivity;
+use Spatie\Activitylog\LogOptions;
 
 class Category extends Model
 {
     use HasFactory, LogsActivity;
 
-    protected $fillable = [
-        'name',
-        'description',
-        'is_active',
-    ];
+    protected $fillable = ['name', 'description'];
 
-    protected $casts = [
-        'is_active' => 'boolean',
-    ];
-
-    /**
-     * Get the products for the category.
-     */
     public function products(): HasMany
     {
         return $this->hasMany(Product::class);
     }
 
-    public function getActivitylogOptions(): \Spatie\Activitylog\LogOptions
+    public function getActivitylogOptions(): LogOptions
     {
-        return \Spatie\Activitylog\LogOptions::defaults()
+        return LogOptions::defaults()
             ->logAll()
             ->logOnlyDirty()
             ->dontSubmitEmptyLogs();
diff --git a/app/Models/Inventory.php b/app/Modules/Inventory/Models/Inventory.php
similarity index 97%
rename from app/Models/Inventory.php
rename to app/Modules/Inventory/Models/Inventory.php
index 4868459..7dcb64b 100644
--- a/app/Models/Inventory.php
+++ b/app/Modules/Inventory/Models/Inventory.php
@@ -1,9 +1,10 @@
 <?php
 
-namespace App\Models;
+namespace App\Modules\Inventory\Models;
 
 use Illuminate\Database\Eloquent\Factories\HasFactory;
 use Illuminate\Database\Eloquent\Model;
+use App\Modules\Procurement\Models\PurchaseOrder; // Cross-module dependency
 
 class Inventory extends Model
 {
diff --git a/app/Models/InventoryTransaction.php b/app/Modules/Inventory/Models/InventoryTransaction.php
similarity index 90%
rename from app/Models/InventoryTransaction.php
rename to app/Modules/Inventory/Models/InventoryTransaction.php
index 0588e08..39b38f1 100644
--- a/app/Models/InventoryTransaction.php
+++ b/app/Modules/Inventory/Models/InventoryTransaction.php
@@ -1,11 +1,10 @@
 <?php
 
-namespace App\Models;
+namespace App\Modules\Inventory\Models;
 
 use Illuminate\Database\Eloquent\Factories\HasFactory;
 use Illuminate\Database\Eloquent\Model;
-use App\Models\Inventory;
-use App\Models\User;
+use App\Modules\Core\Models\User; // Cross-module Core dependency
 
 class InventoryTransaction extends Model
 {
diff --git a/app/Models/Product.php b/app/Modules/Inventory/Models/Product.php
similarity index 96%
rename from app/Models/Product.php
rename to app/Modules/Inventory/Models/Product.php
index 42a6ebd..d7b9402 100644
--- a/app/Models/Product.php
+++ b/app/Modules/Inventory/Models/Product.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace App\Models;
+namespace App\Modules\Inventory\Models;
 
 use Illuminate\Database\Eloquent\Factories\HasFactory;
 use Illuminate\Database\Eloquent\Model;
@@ -9,6 +9,7 @@ use Illuminate\Database\Eloquent\Relations\BelongsTo;
 use Illuminate\Database\Eloquent\Relations\HasMany;
 use Spatie\Activitylog\Traits\LogsActivity;
 use Spatie\Activitylog\LogOptions;
+use App\Modules\Procurement\Models\Vendor; // Cross-module dependency (Procurement)
 
 class Product extends Model
 {
diff --git a/app/Models/Unit.php b/app/Modules/Inventory/Models/Unit.php
similarity index 56%
rename from app/Models/Unit.php
rename to app/Modules/Inventory/Models/Unit.php
index dedf256..f7c8bb9 100644
--- a/app/Models/Unit.php
+++ b/app/Modules/Inventory/Models/Unit.php
@@ -1,24 +1,32 @@
 <?php
 
-namespace App\Models;
+namespace App\Modules\Inventory\Models;
 
 use Illuminate\Database\Eloquent\Factories\HasFactory;
 use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\HasMany;
 use Spatie\Activitylog\Traits\LogsActivity;
+use Spatie\Activitylog\LogOptions;
 
 class Unit extends Model
 {
-    /** @use HasFactory<\Database\Factories\UnitFactory> */
     use HasFactory, LogsActivity;
 
-    protected $fillable = [
-        'name',
-        'code',
-    ];
+    protected $fillable = ['name', 'abbreviation'];
 
-    public function getActivitylogOptions(): \Spatie\Activitylog\LogOptions
+    public function productsAsBase(): HasMany
     {
-        return \Spatie\Activitylog\LogOptions::defaults()
+        return $this->hasMany(Product::class, 'base_unit_id');
+    }
+
+    public function productsAsLarge(): HasMany
+    {
+        return $this->hasMany(Product::class, 'large_unit_id');
+    }
+
+    public function getActivitylogOptions(): LogOptions
+    {
+        return LogOptions::defaults()
             ->logAll()
             ->logOnlyDirty()
             ->dontSubmitEmptyLogs();
diff --git a/app/Models/Warehouse.php b/app/Modules/Inventory/Models/Warehouse.php
similarity index 92%
rename from app/Models/Warehouse.php
rename to app/Modules/Inventory/Models/Warehouse.php
index aa7d64e..2e332e0 100644
--- a/app/Models/Warehouse.php
+++ b/app/Modules/Inventory/Models/Warehouse.php
@@ -1,9 +1,10 @@
 <?php
 
-namespace App\Models;
+namespace App\Modules\Inventory\Models;
 
 use Illuminate\Database\Eloquent\Factories\HasFactory;
 use Illuminate\Database\Eloquent\Model;
+use App\Modules\Procurement\Models\PurchaseOrder; // Cross-module dependency (Procurement)
 
 class Warehouse extends Model
 {
diff --git a/app/Models/WarehouseProductSafetyStock.php b/app/Modules/Inventory/Models/WarehouseProductSafetyStock.php
similarity index 95%
rename from app/Models/WarehouseProductSafetyStock.php
rename to app/Modules/Inventory/Models/WarehouseProductSafetyStock.php
index b967cfc..07754c2 100644
--- a/app/Models/WarehouseProductSafetyStock.php
+++ b/app/Modules/Inventory/Models/WarehouseProductSafetyStock.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace App\Models;
+namespace App\Modules\Inventory\Models;
 
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\Relations\BelongsTo;
diff --git a/app/Modules/Inventory/Routes/web.php b/app/Modules/Inventory/Routes/web.php
new file mode 100644
index 0000000..45af9ac
--- /dev/null
+++ b/app/Modules/Inventory/Routes/web.php
@@ -0,0 +1,80 @@
+<?php
+
+use Illuminate\Support\Facades\Route;
+use App\Modules\Inventory\Controllers\CategoryController;
+use App\Modules\Inventory\Controllers\UnitController;
+use App\Modules\Inventory\Controllers\ProductController;
+use App\Modules\Inventory\Controllers\WarehouseController;
+use App\Modules\Inventory\Controllers\InventoryController;
+use App\Modules\Inventory\Controllers\SafetyStockController;
+use App\Modules\Inventory\Controllers\TransferOrderController;
+
+Route::middleware('auth')->group(function () {
+    
+    // 類別管理 (用於商品對話框) - 需要商品權限
+    Route::middleware('permission:products.view')->group(function () {
+        Route::get('/categories', [CategoryController::class, 'index'])->name('categories.index');
+        Route::post('/categories', [CategoryController::class, 'store'])->middleware('permission:products.create')->name('categories.store');
+        Route::put('/categories/{category}', [CategoryController::class, 'update'])->middleware('permission:products.edit')->name('categories.update');
+        Route::delete('/categories/{category}', [CategoryController::class, 'destroy'])->middleware('permission:products.delete')->name('categories.destroy');
+    });
+
+    // 單位管理 - 需要商品權限
+    Route::middleware('permission:products.create|products.edit')->group(function () {
+        Route::post('/units', [UnitController::class, 'store'])->name('units.store');
+        Route::put('/units/{unit}', [UnitController::class, 'update'])->name('units.update');
+        Route::delete('/units/{unit}', [UnitController::class, 'destroy'])->name('units.destroy');
+    });
+
+    // 商品管理
+    Route::middleware('permission:products.view')->group(function () {
+        Route::get('/products', [ProductController::class, 'index'])->name('products.index');
+        Route::post('/products', [ProductController::class, 'store'])->middleware('permission:products.create')->name('products.store');
+        Route::put('/products/{product}', [ProductController::class, 'update'])->middleware('permission:products.edit')->name('products.update');
+        Route::delete('/products/{product}', [ProductController::class, 'destroy'])->middleware('permission:products.delete')->name('products.destroy');
+    });
+
+    // 倉庫管理
+    Route::middleware('permission:warehouses.view')->group(function () {
+        Route::get('/warehouses', [WarehouseController::class, 'index'])->name('warehouses.index');
+        Route::post('/warehouses', [WarehouseController::class, 'store'])->middleware('permission:warehouses.create')->name('warehouses.store');
+        Route::put('/warehouses/{warehouse}', [WarehouseController::class, 'update'])->middleware('permission:warehouses.edit')->name('warehouses.update');
+        Route::delete('/warehouses/{warehouse}', [WarehouseController::class, 'destroy'])->middleware('permission:warehouses.delete')->name('warehouses.destroy');
+
+        // 倉庫庫存管理 - 需要庫存權限
+        Route::middleware('permission:inventory.view')->group(function () {
+            Route::get('/warehouses/{warehouse}/inventory', [InventoryController::class, 'index'])->name('warehouses.inventory.index');
+            Route::get('/warehouses/{warehouse}/inventory-history', [InventoryController::class, 'history'])->name('warehouses.inventory.history');
+            
+            Route::middleware('permission:inventory.adjust')->group(function () {
+                Route::get('/warehouses/{warehouse}/inventory/create', [InventoryController::class, 'create'])->name('warehouses.inventory.create');
+                Route::post('/warehouses/{warehouse}/inventory', [InventoryController::class, 'store'])->name('warehouses.inventory.store');
+                Route::get('/warehouses/{warehouse}/inventory/{inventoryId}/edit', [InventoryController::class, 'edit'])->name('warehouses.inventory.edit');
+                Route::put('/warehouses/{warehouse}/inventory/{inventoryId}', [InventoryController::class, 'update'])->name('warehouses.inventory.update');
+                Route::delete('/warehouses/{warehouse}/inventory/{inventoryId}', [InventoryController::class, 'destroy'])->name('warehouses.inventory.destroy');
+            });
+
+            // API: 取得商品在特定倉庫的所有批號
+            Route::get('/api/warehouses/{warehouse}/inventory/batches/{productId}', [InventoryController::class, 'getBatches'])
+                ->name('api.warehouses.inventory.batches');
+        });
+
+        // 安全庫存設定
+        Route::middleware('permission:inventory.view')->group(function () {
+            Route::get('/warehouses/{warehouse}/safety-stock', [SafetyStockController::class, 'index'])->name('warehouses.safety-stock.index');
+            Route::middleware('permission:inventory.safety_stock')->group(function () {
+                Route::post('/warehouses/{warehouse}/safety-stock', [SafetyStockController::class, 'store'])->name('warehouses.safety-stock.store');
+                Route::put('/warehouses/{warehouse}/safety-stock/{safetyStock}', [SafetyStockController::class, 'update'])->name('warehouses.safety-stock.update');
+                Route::delete('/warehouses/{warehouse}/safety-stock/{safetyStock}', [SafetyStockController::class, 'destroy'])->name('warehouses.safety-stock.destroy');
+            });
+        });
+    });
+
+    // 撥補單 (在庫存調撥時使用)
+    Route::middleware('permission:inventory.transfer')->group(function () {
+        Route::post('/transfer-orders', [TransferOrderController::class, 'store'])->name('transfer-orders.store');
+    });
+    Route::get('/api/warehouses/{warehouse}/inventories', [TransferOrderController::class, 'getWarehouseInventories'])
+        ->middleware('permission:inventory.view')
+        ->name('api.warehouses.inventories');
+});
diff --git a/app/Http/Controllers/PurchaseOrderController.php b/app/Modules/Procurement/Controllers/PurchaseOrderController.php
similarity index 98%
rename from app/Http/Controllers/PurchaseOrderController.php
rename to app/Modules/Procurement/Controllers/PurchaseOrderController.php
index 6ff462b..c16fced 100644
--- a/app/Http/Controllers/PurchaseOrderController.php
+++ b/app/Modules/Procurement/Controllers/PurchaseOrderController.php
@@ -1,10 +1,12 @@
 <?php
 
-namespace App\Http\Controllers;
+namespace App\Modules\Procurement\Controllers;
 
-use App\Models\PurchaseOrder;
-use App\Models\Vendor;
-use App\Models\Warehouse;
+use App\Http\Controllers\Controller;
+
+use App\Modules\Procurement\Models\PurchaseOrder;
+use App\Modules\Procurement\Models\Vendor;
+use App\Modules\Inventory\Models\Warehouse;
 use Illuminate\Http\Request;
 use Inertia\Inertia;
 use Illuminate\Support\Facades\DB;
@@ -146,9 +148,9 @@ class PurchaseOrderController extends Controller
             // 確保有一個有效的使用者 ID
             $userId = auth()->id();
             if (!$userId) {
-                $user = \App\Models\User::first();
+                $user = \App\Modules\Core\Models\User::first();
                 if (!$user) {
-                    $user = \App\Models\User::create([
+                    $user = \App\Modules\Core\Models\User::create([
                         'name' => '系統管理員',
                         'email' => 'admin@example.com',
                         'password' => bcrypt('password'),
diff --git a/app/Http/Controllers/VendorController.php b/app/Modules/Procurement/Controllers/VendorController.php
similarity index 94%
rename from app/Http/Controllers/VendorController.php
rename to app/Modules/Procurement/Controllers/VendorController.php
index 6919205..8992c62 100644
--- a/app/Http/Controllers/VendorController.php
+++ b/app/Modules/Procurement/Controllers/VendorController.php
@@ -1,8 +1,10 @@
 <?php
 
-namespace App\Http\Controllers;
+namespace App\Modules\Procurement\Controllers;
+
+use App\Http\Controllers\Controller;
+use App\Modules\Procurement\Models\Vendor;
 
-use App\Models\Vendor;
 use Illuminate\Http\Request;
 
 class VendorController extends Controller
@@ -56,7 +58,7 @@ class VendorController extends Controller
         $vendor->load(['products.baseUnit', 'products.largeUnit']);
         return \Inertia\Inertia::render('Vendor/Show', [
             'vendor' => $vendor,
-            'products' => \App\Models\Product::with('baseUnit')->get(),
+            'products' => \App\Modules\Inventory\Models\Product::with('baseUnit')->get(),
         ]);
     }
 
diff --git a/app/Http/Controllers/VendorProductController.php b/app/Modules/Procurement/Controllers/VendorProductController.php
similarity index 91%
rename from app/Http/Controllers/VendorProductController.php
rename to app/Modules/Procurement/Controllers/VendorProductController.php
index 6a25f8f..4b4fad9 100644
--- a/app/Http/Controllers/VendorProductController.php
+++ b/app/Modules/Procurement/Controllers/VendorProductController.php
@@ -1,8 +1,10 @@
 <?php
 
-namespace App\Http\Controllers;
+namespace App\Modules\Procurement\Controllers;
+
+use App\Http\Controllers\Controller;
+use App\Modules\Procurement\Models\Vendor;
 
-use App\Models\Vendor;
 use Illuminate\Http\Request;
 use Illuminate\Support\Facades\Log;
 
@@ -28,7 +30,7 @@ class VendorProductController extends Controller
         ]);
 
         // 記錄操作
-        $product = \App\Models\Product::find($validated['product_id']);
+        $product = \App\Modules\Inventory\Models\Product::find($validated['product_id']);
         activity()
             ->performedOn($vendor)
             ->withProperties([
@@ -66,7 +68,7 @@ class VendorProductController extends Controller
         ]);
 
         // 記錄操作
-        $product = \App\Models\Product::find($productId);
+        $product = \App\Modules\Inventory\Models\Product::find($productId);
         activity()
             ->performedOn($vendor)
             ->withProperties([
@@ -95,7 +97,7 @@ class VendorProductController extends Controller
     public function destroy(Vendor $vendor, $productId)
     {
         // 記錄操作 (需在 detach 前獲取資訊)
-        $product = \App\Models\Product::find($productId);
+        $product = \App\Modules\Inventory\Models\Product::find($productId);
         $old_price = $vendor->products()->where('product_id', $productId)->first()?->pivot?->last_price;
         
         $vendor->products()->detach($productId);
diff --git a/app/Modules/Procurement/Models/PurchaseOrder.php b/app/Modules/Procurement/Models/PurchaseOrder.php
new file mode 100644
index 0000000..0161889
--- /dev/null
+++ b/app/Modules/Procurement/Models/PurchaseOrder.php
@@ -0,0 +1,79 @@
+<?php
+
+namespace App\Modules\Procurement\Models;
+
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+use App\Modules\Inventory\Models\Warehouse;
+use App\Modules\Core\Models\User;
+
+class PurchaseOrder extends Model
+{
+    /** @use HasFactory<\Database\Factories\PurchaseOrderFactory> */
+    use HasFactory;
+    use \Spatie\Activitylog\Traits\LogsActivity;
+
+    protected $fillable = [
+        'po_number',
+        'vendor_id',
+        'warehouse_id',
+        'user_id',
+        'order_date',
+        'expected_delivery_date',
+        'status',
+        'total_amount',
+        'notes',
+    ];
+
+    protected $casts = [
+        'order_date' => 'date',
+        'expected_delivery_date' => 'date',
+        'total_amount' => 'decimal:2',
+    ];
+
+    public function getActivitylogOptions(): \Spatie\Activitylog\LogOptions
+    {
+        return \Spatie\Activitylog\LogOptions::defaults()
+            ->logAll()
+            ->logOnlyDirty()
+            ->dontSubmitEmptyLogs();
+    }
+
+    public function tapActivity(\Spatie\Activitylog\Contracts\Activity $activity, string $eventName)
+    {
+        $snapshot = $activity->properties['snapshot'] ?? [];
+        
+        $snapshot['po_number'] = $this->po_number;
+        
+        if ($this->vendor) {
+            $snapshot['vendor_name'] = $this->vendor->name;
+        }
+        if ($this->warehouse) {
+            $snapshot['warehouse_name'] = $this->warehouse->name;
+        }
+
+        $activity->properties = $activity->properties->merge([
+            'snapshot' => $snapshot
+        ]);
+    }
+
+    public function vendor(): \Illuminate\Database\Eloquent\Relations\BelongsTo
+    {
+        return $this->belongsTo(Vendor::class);
+    }
+
+    public function warehouse(): \Illuminate\Database\Eloquent\Relations\BelongsTo
+    {
+        return $this->belongsTo(Warehouse::class);
+    }
+
+    public function user(): \Illuminate\Database\Eloquent\Relations\BelongsTo
+    {
+        return $this->belongsTo(User::class);
+    }
+
+    public function items(): \Illuminate\Database\Eloquent\Relations\HasMany
+    {
+        return $this->hasMany(PurchaseOrderItem::class);
+    }
+}
diff --git a/app/Modules/Procurement/Models/PurchaseOrderItem.php b/app/Modules/Procurement/Models/PurchaseOrderItem.php
new file mode 100644
index 0000000..de53384
--- /dev/null
+++ b/app/Modules/Procurement/Models/PurchaseOrderItem.php
@@ -0,0 +1,44 @@
+<?php
+
+namespace App\Modules\Procurement\Models;
+
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+use App\Modules\Inventory\Models\Product;
+
+class PurchaseOrderItem extends Model
+{
+    /** @use HasFactory<\Database\Factories\PurchaseOrderItemFactory> */
+    use HasFactory;
+
+    protected $fillable = [
+        'purchase_order_id',
+        'product_id',
+        'quantity',
+        'unit_price',
+        'subtotal',
+        // 驗收欄位
+        'received_quantity',
+        // 批號與效期 (驗收時填寫)
+        'batch_number',
+        'expiry_date',
+    ];
+
+    protected $casts = [
+        'quantity' => 'decimal:2',
+        'unit_price' => 'decimal:4',
+        'subtotal' => 'decimal:2',
+        'received_quantity' => 'decimal:2',
+        'expiry_date' => 'date',
+    ];
+
+    public function purchaseOrder(): \Illuminate\Database\Eloquent\Relations\BelongsTo
+    {
+        return $this->belongsTo(PurchaseOrder::class);
+    }
+
+    public function product(): \Illuminate\Database\Eloquent\Relations\BelongsTo
+    {
+        return $this->belongsTo(Product::class);
+    }
+}
diff --git a/app/Models/Vendor.php b/app/Modules/Procurement/Models/Vendor.php
similarity index 53%
rename from app/Models/Vendor.php
rename to app/Modules/Procurement/Models/Vendor.php
index 85e4f12..144c29a 100644
--- a/app/Models/Vendor.php
+++ b/app/Modules/Procurement/Models/Vendor.php
@@ -1,38 +1,35 @@
 <?php
 
-namespace App\Models;
+namespace App\Modules\Procurement\Models;
 
+use Illuminate\Database\Eloquent\Factories\HasFactory;
 use Illuminate\Database\Eloquent\Model;
-use Illuminate\Database\Eloquent\Relations\BelongsToMany;
-use Illuminate\Database\Eloquent\Relations\HasMany;
 use Spatie\Activitylog\Traits\LogsActivity;
 use Spatie\Activitylog\LogOptions;
+use App\Modules\Inventory\Models\Product;
 
 class Vendor extends Model
 {
-    use LogsActivity;
+    /** @use HasFactory<\Database\Factories\VendorFactory> */
+    use HasFactory, LogsActivity;
 
     protected $fillable = [
         'code',
         'name',
-        'short_name',
-        'tax_id',
-        'owner',
-        'contact_name',
-        'tel',
-        'phone',
+        'contact_person',
         'email',
+        'phone',
         'address',
-        'remark'
+        'tax_id',
+        'payment_terms',
     ];
-    public function products(): BelongsToMany
+
+    public function products(): \Illuminate\Database\Eloquent\Relations\BelongsToMany
     {
-        return $this->belongsToMany(Product::class, 'product_vendor')
-                    ->withPivot('last_price')
-                    ->withTimestamps();
+        return $this->belongsToMany(Product::class)->withPivot('last_price')->withTimestamps();
     }
 
-    public function purchaseOrders(): HasMany
+    public function purchaseOrders(): \Illuminate\Database\Eloquent\Relations\HasMany
     {
         return $this->hasMany(PurchaseOrder::class);
     }
@@ -49,12 +46,8 @@ class Vendor extends Model
     {
         $properties = $activity->properties;
         
-        // Store name in 'snapshot' for context, keeping 'attributes' clean
         $snapshot = $properties['snapshot'] ?? [];
-        // Only set name if it's not already set (e.g. by controller for specific context like supply product)
-        if (!isset($snapshot['name'])) {
-            $snapshot['name'] = $this->name;
-        }
+        $snapshot['name'] = $this->name;
         $properties['snapshot'] = $snapshot;
 
         $activity->properties = $properties;
diff --git a/app/Modules/Procurement/Routes/web.php b/app/Modules/Procurement/Routes/web.php
new file mode 100644
index 0000000..5275186
--- /dev/null
+++ b/app/Modules/Procurement/Routes/web.php
@@ -0,0 +1,38 @@
+<?php
+
+use Illuminate\Support\Facades\Route;
+use App\Modules\Procurement\Controllers\VendorController;
+use App\Modules\Procurement\Controllers\VendorProductController;
+use App\Modules\Procurement\Controllers\PurchaseOrderController;
+
+Route::middleware('auth')->group(function () {
+    // 廠商管理
+    Route::middleware('permission:vendors.view')->group(function () {
+        Route::get('/vendors', [VendorController::class, 'index'])->name('vendors.index');
+        Route::get('/vendors/{vendor}', [VendorController::class, 'show'])->name('vendors.show');
+        Route::post('/vendors', [VendorController::class, 'store'])->middleware('permission:vendors.create')->name('vendors.store');
+        Route::put('/vendors/{vendor}', [VendorController::class, 'update'])->middleware('permission:vendors.edit')->name('vendors.update');
+        Route::delete('/vendors/{vendor}', [VendorController::class, 'destroy'])->middleware('permission:vendors.delete')->name('vendors.destroy');
+
+        // 供貨商品相關路由
+        Route::post('/vendors/{vendor}/products', [VendorProductController::class, 'store'])->middleware('permission:vendors.edit')->name('vendors.products.store');
+        Route::put('/vendors/{vendor}/products/{product}', [VendorProductController::class, 'update'])->middleware('permission:vendors.edit')->name('vendors.products.update');
+        Route::delete('/vendors/{vendor}/products/{product}', [VendorProductController::class, 'destroy'])->middleware('permission:vendors.edit')->name('vendors.products.destroy');
+    });
+
+    // 採購單管理
+    Route::middleware('permission:purchase_orders.view')->group(function () {
+        Route::get('/purchase-orders', [PurchaseOrderController::class, 'index'])->name('purchase-orders.index');
+        
+        Route::middleware('permission:purchase_orders.create')->group(function () {
+            Route::get('/purchase-orders/create', [PurchaseOrderController::class, 'create'])->name('purchase-orders.create');
+            Route::post('/purchase-orders', [PurchaseOrderController::class, 'store'])->name('purchase-orders.store');
+        });
+
+        Route::get('/purchase-orders/{id}', [PurchaseOrderController::class, 'show'])->name('purchase-orders.show');
+        
+        Route::get('/purchase-orders/{id}/edit', [PurchaseOrderController::class, 'edit'])->middleware('permission:purchase_orders.edit')->name('purchase-orders.edit');
+        Route::put('/purchase-orders/{id}', [PurchaseOrderController::class, 'update'])->middleware('permission:purchase_orders.edit')->name('purchase-orders.update');
+        Route::delete('/purchase-orders/{id}', [PurchaseOrderController::class, 'destroy'])->middleware('permission:purchase_orders.delete')->name('purchase-orders.destroy');
+    });
+});
diff --git a/app/Http/Controllers/ProductionOrderController.php b/app/Modules/Production/Controllers/ProductionOrderController.php
similarity index 98%
rename from app/Http/Controllers/ProductionOrderController.php
rename to app/Modules/Production/Controllers/ProductionOrderController.php
index 887dac4..c312e9e 100644
--- a/app/Http/Controllers/ProductionOrderController.php
+++ b/app/Modules/Production/Controllers/ProductionOrderController.php
@@ -1,13 +1,14 @@
 <?php
 
-namespace App\Http\Controllers;
+namespace App\Modules\Production\Controllers;
 
-use App\Models\Inventory;
-use App\Models\Product;
-use App\Models\ProductionOrder;
-use App\Models\ProductionOrderItem;
-use App\Models\Unit;
-use App\Models\Warehouse;
+use App\Http\Controllers\Controller;
+
+use App\Modules\Inventory\Models\Product;
+use App\Modules\Production\Models\ProductionOrder;
+use App\Modules\Production\Models\ProductionOrderItem;
+use App\Modules\Inventory\Models\Unit;
+use App\Modules\Inventory\Models\Warehouse;
 use Illuminate\Http\Request;
 use Illuminate\Support\Facades\DB;
 use Inertia\Inertia;
diff --git a/app/Modules/Production/Models/ProductionOrder.php b/app/Modules/Production/Models/ProductionOrder.php
new file mode 100644
index 0000000..6617b2d
--- /dev/null
+++ b/app/Modules/Production/Models/ProductionOrder.php
@@ -0,0 +1,70 @@
+<?php
+
+namespace App\Modules\Production\Models;
+
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+use App\Modules\Inventory\Models\Product;
+use App\Modules\Inventory\Models\Warehouse;
+use App\Modules\Core\Models\User;
+
+class ProductionOrder extends Model
+{
+    /** @use HasFactory<\Database\Factories\ProductionOrderFactory> */
+    use HasFactory;
+
+    protected $fillable = [
+        'code',
+        'product_id',
+        'warehouse_id',
+        'output_quantity',
+        'output_batch_number',
+        'output_box_count',
+        'production_date',
+        'expiry_date',
+        'user_id',
+        'status',
+        'remark',
+    ];
+
+    public static function generateCode()
+    {
+        $prefix = 'PO' . now()->format('Ymd');
+        $lastOrder = self::where('code', 'like', $prefix . '%')->latest()->first();
+        if ($lastOrder) {
+            $lastSequence = intval(substr($lastOrder->code, -3));
+            $sequence = str_pad($lastSequence + 1, 3, '0', STR_PAD_LEFT);
+        } else {
+            $sequence = '001';
+        }
+        return $prefix . $sequence;
+    }
+
+    protected $casts = [
+        'order_date' => 'date',
+        'start_date' => 'datetime',
+        'completion_date' => 'datetime',
+        'quantity' => 'decimal:2',
+        'produced_quantity' => 'decimal:2',
+    ];
+
+    public function product(): \Illuminate\Database\Eloquent\Relations\BelongsTo
+    {
+        return $this->belongsTo(Product::class);
+    }
+
+    public function warehouse(): \Illuminate\Database\Eloquent\Relations\BelongsTo
+    {
+        return $this->belongsTo(Warehouse::class);
+    }
+
+    public function user(): \Illuminate\Database\Eloquent\Relations\BelongsTo
+    {
+        return $this->belongsTo(User::class);
+    }
+
+    public function items(): \Illuminate\Database\Eloquent\Relations\HasMany
+    {
+        return $this->hasMany(ProductionOrderItem::class);
+    }
+}
diff --git a/app/Modules/Production/Models/ProductionOrderItem.php b/app/Modules/Production/Models/ProductionOrderItem.php
new file mode 100644
index 0000000..23bc855
--- /dev/null
+++ b/app/Modules/Production/Models/ProductionOrderItem.php
@@ -0,0 +1,44 @@
+<?php
+
+namespace App\Modules\Production\Models;
+
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+use App\Modules\Inventory\Models\Product;
+
+class ProductionOrderItem extends Model
+{
+    /** @use HasFactory<\Database\Factories\ProductionOrderItemFactory> */
+    use HasFactory;
+
+    protected $fillable = [
+        'production_order_id',
+        'inventory_id',
+        'quantity_used',
+        'unit_id',
+    ];
+
+    protected $casts = [
+        'quantity_used' => 'decimal:4',
+    ];
+
+    public function inventory()
+    {
+        return $this->belongsTo(\App\Modules\Inventory\Models\Inventory::class);
+    }
+
+    public function unit()
+    {
+        return $this->belongsTo(\App\Modules\Inventory\Models\Unit::class);
+    }
+
+    public function productionOrder(): \Illuminate\Database\Eloquent\Relations\BelongsTo
+    {
+        return $this->belongsTo(ProductionOrder::class);
+    }
+
+    public function product(): \Illuminate\Database\Eloquent\Relations\BelongsTo
+    {
+        return $this->belongsTo(Product::class);
+    }
+}
diff --git a/app/Modules/Production/Routes/web.php b/app/Modules/Production/Routes/web.php
new file mode 100644
index 0000000..b4e8a66
--- /dev/null
+++ b/app/Modules/Production/Routes/web.php
@@ -0,0 +1,28 @@
+<?php
+
+use Illuminate\Support\Facades\Route;
+use App\Modules\Production\Controllers\ProductionOrderController;
+
+Route::middleware('auth')->group(function () {
+    // 生產管理
+    Route::middleware('permission:production_orders.view')->group(function () {
+        Route::get('/production-orders', [ProductionOrderController::class, 'index'])->name('production-orders.index');
+        
+        Route::middleware('permission:production_orders.create')->group(function () {
+            Route::get('/production-orders/create', [ProductionOrderController::class, 'create'])->name('production-orders.create');
+            Route::post('/production-orders', [ProductionOrderController::class, 'store'])->name('production-orders.store');
+        });
+        
+        Route::get('/production-orders/{productionOrder}', [ProductionOrderController::class, 'show'])->name('production-orders.show');
+        
+        Route::middleware('permission:production_orders.edit')->group(function () {
+            Route::get('/production-orders/{productionOrder}/edit', [ProductionOrderController::class, 'edit'])->name('production-orders.edit');
+            Route::put('/production-orders/{productionOrder}', [ProductionOrderController::class, 'update'])->name('production-orders.update');
+        });
+    });
+
+    // 生產管理 API
+    Route::get('/api/production/warehouses/{warehouse}/inventories', [ProductionOrderController::class, 'getWarehouseInventories'])
+        ->middleware('permission:production_orders.create')
+        ->name('api.production.warehouses.inventories');
+});
diff --git a/app/Providers/ModuleServiceProvider.php b/app/Providers/ModuleServiceProvider.php
new file mode 100644
index 0000000..6e81662
--- /dev/null
+++ b/app/Providers/ModuleServiceProvider.php
@@ -0,0 +1,40 @@
+<?php
+
+namespace App\Providers;
+
+use Illuminate\Support\Facades\File;
+use Illuminate\Support\Facades\Route;
+use Illuminate\Support\ServiceProvider;
+
+class ModuleServiceProvider extends ServiceProvider
+{
+    /**
+     * Register services.
+     */
+    public function register(): void
+    {
+        //
+    }
+
+    /**
+     * Bootstrap services.
+     */
+    public function boot(): void
+    {
+        $modulesPath = app_path('Modules');
+
+        if (File::exists($modulesPath)) {
+            $modules = File::directories($modulesPath);
+
+            foreach ($modules as $module) {
+                // $moduleName = basename($module);
+                $routesPath = $module . '/Routes/web.php';
+
+                if (File::exists($routesPath)) {
+                    Route::middleware('web')
+                        ->group($routesPath);
+                }
+            }
+        }
+    }
+}
diff --git a/bootstrap/providers.php b/bootstrap/providers.php
index c6a4f12..7e01db1 100644
--- a/bootstrap/providers.php
+++ b/bootstrap/providers.php
@@ -3,4 +3,5 @@
 return [
     App\Providers\AppServiceProvider::class,
     App\Providers\TenancyServiceProvider::class,
+    App\Providers\ModuleServiceProvider::class,
 ];
diff --git a/composer.json b/composer.json
index 78f8669..460cb70 100644
--- a/composer.json
+++ b/composer.json
@@ -31,6 +31,7 @@
     "autoload": {
         "psr-4": {
             "App\\": "app/",
+            "App\\Modules\\": "app/Modules/",
             "Database\\Factories\\": "database/factories/",
             "Database\\Seeders\\": "database/seeders/"
         }
@@ -92,4 +93,4 @@
     },
     "minimum-stability": "stable",
     "prefer-stable": true
-}
+}
\ No newline at end of file
diff --git a/config/auth.php b/config/auth.php
index 7d1eb0d..3e9d705 100644
--- a/config/auth.php
+++ b/config/auth.php
@@ -62,7 +62,7 @@ return [
     'providers' => [
         'users' => [
             'driver' => 'eloquent',
-            'model' => env('AUTH_MODEL', App\Models\User::class),
+            'model' => env('AUTH_MODEL', App\Modules\Core\Models\User::class),
         ],
 
         // 'users' => [
diff --git a/config/permission.php b/config/permission.php
index 03bf909..5710828 100644
--- a/config/permission.php
+++ b/config/permission.php
@@ -24,7 +24,7 @@ return [
          * `Spatie\Permission\Contracts\Role` contract.
          */
 
-        'role' => App\Models\Role::class,
+        'role' => App\Modules\Core\Models\Role::class,
 
     ],
 
diff --git a/config/tenancy.php b/config/tenancy.php
index 6ce878c..1dc715d 100644
--- a/config/tenancy.php
+++ b/config/tenancy.php
@@ -3,7 +3,7 @@
 declare(strict_types=1);
 
 use Stancl\Tenancy\Database\Models\Domain;
-use App\Models\Tenant;
+use App\Modules\Core\Models\Tenant;
 
 return [
     'tenant_model' => Tenant::class,
diff --git a/database/factories/ProductFactory.php b/database/factories/ProductFactory.php
index 1f620c0..04a2ad6 100644
--- a/database/factories/ProductFactory.php
+++ b/database/factories/ProductFactory.php
@@ -2,11 +2,11 @@
 
 namespace Database\Factories;
 
-use App\Models\Category;
+use App\Modules\Inventory\Models\Category;
 use Illuminate\Database\Eloquent\Factories\Factory;
 
 /**
- * @extends \Illuminate\Database\Eloquent\Factories\Factory<\App\Models\Product>
+ * @extends \Illuminate\Database\Eloquent\Factories\Factory<\App\Modules\Inventory\Models\Product>
  */
 class ProductFactory extends Factory
 {
diff --git a/database/factories/UserFactory.php b/database/factories/UserFactory.php
index 584104c..a32daed 100644
--- a/database/factories/UserFactory.php
+++ b/database/factories/UserFactory.php
@@ -7,7 +7,7 @@ use Illuminate\Support\Facades\Hash;
 use Illuminate\Support\Str;
 
 /**
- * @extends \Illuminate\Database\Eloquent\Factories\Factory<\App\Models\User>
+ * @extends \Illuminate\Database\Eloquent\Factories\Factory<\App\Modules\Core\Models\User>
  */
 class UserFactory extends Factory
 {
diff --git a/database/seeders/CategorySeeder.php b/database/seeders/CategorySeeder.php
index 9714d65..6234323 100644
--- a/database/seeders/CategorySeeder.php
+++ b/database/seeders/CategorySeeder.php
@@ -2,7 +2,7 @@
 
 namespace Database\Seeders;
 
-use App\Models\Category;
+use App\Modules\Inventory\Models\Category;
 use Illuminate\Database\Seeder;
 
 class CategorySeeder extends Seeder
diff --git a/database/seeders/DatabaseSeeder.php b/database/seeders/DatabaseSeeder.php
index 1468bcc..56e17a8 100644
--- a/database/seeders/DatabaseSeeder.php
+++ b/database/seeders/DatabaseSeeder.php
@@ -2,7 +2,7 @@
 
 namespace Database\Seeders;
 
-use App\Models\User;
+use App\Modules\Core\Models\User;
 use Illuminate\Database\Console\Seeds\WithoutModelEvents;
 use Illuminate\Database\Seeder;
 
diff --git a/database/seeders/PermissionSeeder.php b/database/seeders/PermissionSeeder.php
index 9bf8fdf..bf46f4a 100644
--- a/database/seeders/PermissionSeeder.php
+++ b/database/seeders/PermissionSeeder.php
@@ -5,7 +5,7 @@ namespace Database\Seeders;
 use Illuminate\Database\Seeder;
 use Spatie\Permission\Models\Role;
 use Spatie\Permission\Models\Permission;
-use App\Models\User;
+use App\Modules\Core\Models\User;
 
 class PermissionSeeder extends Seeder
 {
diff --git a/database/seeders/ProductSeeder.php b/database/seeders/ProductSeeder.php
index ba86999..5c92a49 100644
--- a/database/seeders/ProductSeeder.php
+++ b/database/seeders/ProductSeeder.php
@@ -2,8 +2,8 @@
 
 namespace Database\Seeders;
 
-use App\Models\Category;
-use App\Models\Product;
+use App\Modules\Inventory\Models\Category;
+use App\Modules\Inventory\Models\Product;
 use Illuminate\Database\Seeder;
 
 class ProductSeeder extends Seeder
diff --git a/database/seeders/TenantDatabaseSeeder.php b/database/seeders/TenantDatabaseSeeder.php
index 7a86914..dfc3cd5 100644
--- a/database/seeders/TenantDatabaseSeeder.php
+++ b/database/seeders/TenantDatabaseSeeder.php
@@ -3,7 +3,7 @@
 namespace Database\Seeders;
 
 use Illuminate\Database\Seeder;
-use App\Models\User;
+use App\Modules\Core\Models\User;
 use Spatie\Permission\Models\Role;
 use Spatie\Permission\Models\Permission;
 
diff --git a/database/seeders/UnitSeeder.php b/database/seeders/UnitSeeder.php
index 07eb690..d914994 100644
--- a/database/seeders/UnitSeeder.php
+++ b/database/seeders/UnitSeeder.php
@@ -2,7 +2,7 @@
 
 namespace Database\Seeders;
 
-use App\Models\Unit;
+use App\Modules\Inventory\Models\Unit;
 use Illuminate\Database\Seeder;
 
 class UnitSeeder extends Seeder
diff --git a/database/seeders/VendorSeeder.php b/database/seeders/VendorSeeder.php
index 95fc146..7fc8260 100644
--- a/database/seeders/VendorSeeder.php
+++ b/database/seeders/VendorSeeder.php
@@ -2,7 +2,7 @@
 
 namespace Database\Seeders;
 
-use App\Models\Vendor;
+use App\Modules\Procurement\Models\Vendor;
 use Illuminate\Database\Seeder;
 
 class VendorSeeder extends Seeder
diff --git a/docs/FRAMEWORK_SPEC.md b/docs/FRAMEWORK_SPEC.md
new file mode 100644
index 0000000..53c0ce9
--- /dev/null
+++ b/docs/FRAMEWORK_SPEC.md
@@ -0,0 +1,60 @@
+# 開發框架規範說明書：ERP 系統 (star-erp)
+
+## 1. 專案概述
+*   **目標**： 打造一個強大且穩定的 ERP 後台管理系統。
+*   **核心架構**： 採用 **模組化單體式架構 (Modular Monolith)** 配現代化前端。使用 Laravel、Inertia.js 及 React。
+*   **工作流程**： 將 UI/UX 設計師提供的 React 原始碼，透過 Inertia.js 整合進 Laravel 環境中。後端邏輯依據「業務領域」拆分為獨立模組。
+
+## 2. 技術棧 (Tech Stack)
+*   **後端**： PHP 8.5 / Laravel 12
+*   **前端橋樑**： Inertia.js (不使用傳統 RESTful API 串接頁面，改用 Inertia 協議)
+*   **前端庫**： React (以 Functional Components 與 Hooks 為主)
+*   **樣式處理**： Tailwind CSS (確保與 UI/UX 設計稿完全一致)
+*   **資料庫**： MySQL 8.0
+*   **開發環境**： Laravel Sail (Docker / WSL2)
+*   **未來擴充**： 針對高併發或跨平台模組，預留 Golang 微服務接口。
+
+## 3. 目錄結構與慣例
+
+### 3.1 後端 (Laravel - Modular Monolith)
+系統採用模組化架構，核心邏輯位於 `app/Modules/` 下：
+
+*   **Modules**： 位於 `app/Modules/{ModuleName}/`。
+    *   **Controllers**： `app/Modules/{ModuleName}/Controllers/`。必須回傳 `Inertia::render()`。
+    *   **Models**： `app/Modules/{ModuleName}/Models/`。
+    *   **Routes**： `app/Modules/{ModuleName}/Routes/web.php`。各模組獨立管理路由。
+*   **Global Routes**： `routes/web.php` 僅保留全域通用路由或作為模組路由的載入點。
+
+### 3.2 前端 (React)
+*   **Pages (頁面)**： 位於 `resources/js/Pages/`。每個檔案代表一個完整的路由視圖。
+*   **Components (組件)**： 位於 `resources/js/Components/`。存放由 UI/UX 團隊提供的可重複使用 UI 元件。
+*   **Layouts (版面)**： 位於 `resources/js/Layouts/`。定義 ERP 的通用版面。
+
+## 4. 整合指南 (UI/UX 轉換至 Laravel)
+*   **組件遷移**： 將 UI/UX 的 React 原始碼移入 `resources/js/` 時，應進行「原子化」拆解，提高元件複用率。
+*   **資料傳遞**： 透過 Laravel Controller 的 props 傳送動態資料給 React。優先使用 Inertia 資料流，避免初次渲染時使用 axios。
+*   **狀態管理**： 優先使用 Inertia 內建的狀態管理與 useForm hook 處理表單提交。
+
+## 5. 開發標準 (Coding Standards)
+*   **命名規範**：
+    *   Controllers: `PascalCaseController.php`
+    *   React Components: `PascalCase.jsx`
+    *   Routes: `kebab-case` (小寫橫線分隔)
+*   **回傳格式**： 所有的前後端溝通需維持一致的 JSON 結構，特別是驗證錯誤 (Validation Errors) 與閃存訊息 (Flash Messages)。
+
+## 6. AI 協作規則 (給 Antigravity AI)
+*   **角色設定**： 你是一位專業的全端開發工程師助手。
+*   **代碼生成指令**：
+    *   所有的解釋說明請使用 **繁體中文**。
+    *   生成 React 組件時，必須符合專案現有的 Tailwind CSS 配置。
+    *   必須考慮 ERP 邏輯（例如：權限判斷、操作日誌、資料完整性）。
+    *   新增功能時，請先判斷應歸屬於哪個 Module，並建立在 `app/Modules/` 對應目錄下。
+
+## 7. 運行機制 (Docker / Sail)
+由於專案運行在 Docker 容器環境中，請勿直接在宿主機 (Host) 執行 php 或 composer 指令。請使用專案內建的 `sail` 指令：
+
+*   **啟動環境**： `./vendor/bin/sail up -d`
+*   **執行 PHP 指令**： `./vendor/bin/sail php -v`
+*   **執行 Artisan 指令**： `./vendor/bin/sail artisan route:list`
+*   **執行 Composer**： `./vendor/bin/sail composer install`
+*   **執行 Node/NPM**： `./vendor/bin/sail npm run dev`
\ No newline at end of file
diff --git a/docs/MODULAR_ARCHITECTURE.md b/docs/MODULAR_ARCHITECTURE.md
new file mode 100644
index 0000000..481fe3d
--- /dev/null
+++ b/docs/MODULAR_ARCHITECTURE.md
@@ -0,0 +1,92 @@
+# Star ERP 模組化單體架構 (Modular Monolith)
+
+本文件記錄 Star ERP 的模組化架構現狀、模組邊界定義以及各模組包含之詳細功能。
+
+## 1. 架構概觀
+系統採用 **模組化單體 (Modular Monolith)** 架構。
+- **後端**：依據業務領域 (Domain) 拆分為獨立模組，位於 `app/Modules/{ModuleName}`。
+- **前端**：維持統一的 Inertia/React 架構，位於 `resources/js`。
+- **通訊**：模組間優先透過 Service Class 溝通，但允許在同一資料庫內進行關聯查詢 (Eloquent Relationships)。
+
+---
+
+## 2. 模組列表與功能 (Modules Manifest)
+
+### ✅ Inventory (庫存模組)
+**定位**：處理所有與「商品」及「實體庫存」相關的業務。通用於所有產業。
+- **Namespace**: `App\Modules\Inventory`
+- **狀態**: 🟢 已遷移 (Migrated)
+- **功能細項**:
+    - **商品基礎資料**:
+        - 商品管理 (CRUD、多規格)
+        - 商品分類 (Category)
+        - 計量單位 (Unit, 支援大小單位換算)
+    - **倉庫管理**:
+        - 多倉庫設定 (Warehouse)
+        - 庫存查詢 (Inventory Lookup)
+        - 庫存異動歷史 (Transaction History)
+    - **庫存作業**:
+        - 手動庫存調整 (Adjustments)
+        - 庫存調撥 (Transfer Orders)
+        - 批號追蹤 (Batch Tracking, 基礎版)
+    - **監控**:
+        - 安全庫存設定 (Safety Stock)
+
+---
+
+### ✅ Core (系統核心模組)
+**定位**：系統基礎設施，處理帳號、權限與租戶管理。
+- **Namespace**: `App\Modules\Core`
+- **狀態**: 🟢 已遷移 (Migrated)
+- **功能細項**:
+    - **身分驗證**: 登入/登出 (Auth)
+    - **使用者管理**: User CRUD
+    - **權限控制**: 角色與權限 (RBAC)
+    - **多租戶**: 租戶管理 (Tenancy)
+    - **系統監控**: 操作紀錄 (Activity Log)
+    - **個人化**: 個人設定 (Profile)
+
+---
+
+### ✅ Procurement (採購模組)
+**定位**：供應鏈管理，處理進貨源頭。
+- **Namespace**: `App\Modules\Procurement`
+- **狀態**: 🟢 已遷移 (Migrated)
+- **功能細項**:
+    - **供應商管理**: 廠商資料 (Vendor)、供貨商品清單
+    - **採購作業**: 採購單 (Purchase Order)、進貨驗收
+
+---
+
+### ✅ Production (生產模組)
+**定位**：製造與加工，食品業/製造業核心。
+- **Namespace**: `App\Modules\Production`
+- **狀態**: 🟢 已遷移 (Migrated)
+- **功能細項**:
+    - **工單管理**: 生產工單 (Production Order)
+    - **配方管理**: (規劃中) Recipe
+    - **領料與耗用**: 原料扣庫
+
+---
+
+### ✅ Finance (財務模組)
+**定位**：經營分析與帳務。
+- **Namespace**: `App\Modules\Finance`
+- **狀態**: 🟢 已遷移 (Migrated)
+- **功能細項**:
+    - **費用管理**: 公共事業費 (Utility Fee)
+    - **報表**: 會計報表 (Accounting Reports)
+    - **成本分析**: (規劃中) Costing
+
+---
+
+## 3. 未來擴充模組 (Future Verticals)
+
+針對特定產業的垂直擴充模組（可插拔）：
+
+| 模組名稱 | 適用產業 | 關鍵功能 |
+| :--- | :--- | :--- |
+| **Logistics** | 物流/零售 | 路徑規劃、裝車單、司機派送 |
+| **Food** | 食品/餐飲 | 嚴格效期控管 (FEFO)、雙向溯源、營養成分標示 |
+| **Retail** | 零售/電商 | 全通路訂單整合、促銷引擎 (Promotion)、POS 介接 |
+| **Cosmetics**| 化妝品 | 成分分析、過敏原管理 |
diff --git a/resources/js/utils/format.ts b/resources/js/utils/format.ts
index 498f298..77da518 100644
--- a/resources/js/utils/format.ts
+++ b/resources/js/utils/format.ts
@@ -5,14 +5,16 @@
 /**
  * 格式化數字為千分位格式
  */
-export const formatNumber = (num: number): string => {
+export const formatNumber = (num: number | null | undefined): string => {
+  if (num === null || num === undefined) return "0";
   return num.toLocaleString();
 };
 
 /**
  * 格式化貨幣（NT$）
  */
-export const formatCurrency = (num: number): string => {
+export const formatCurrency = (num: number | null | undefined): string => {
+  if (num === null || num === undefined) return "NT$ 0";
   return `NT$ ${num.toLocaleString()}`;
 };
 
diff --git a/routes/web.php b/routes/web.php
index ce73284..a1cbbdc 100644
--- a/routes/web.php
+++ b/routes/web.php
@@ -2,211 +2,37 @@
 
 use Illuminate\Support\Facades\Route;
 use Inertia\Inertia;
-use App\Http\Controllers\CategoryController;
-use App\Http\Controllers\VendorController;
-use App\Http\Controllers\VendorProductController;
-use App\Http\Controllers\DashboardController;
-use App\Http\Controllers\ProductController;
-use App\Http\Controllers\Auth\LoginController;
-use App\Http\Controllers\PurchaseOrderController;
-use App\Http\Controllers\WarehouseController;
-use App\Http\Controllers\InventoryController;
-use App\Http\Controllers\SafetyStockController;
-use App\Http\Controllers\TransferOrderController;
-use App\Http\Controllers\UnitController;
-use App\Http\Controllers\Admin\RoleController;
-use App\Http\Controllers\Admin\UserController;
-use App\Http\Controllers\Admin\ActivityLogController;
-use App\Http\Controllers\ProfileController;
-use App\Http\Controllers\UtilityFeeController;
-use App\Http\Controllers\AccountingReportController;
-use App\Http\Controllers\ProductionOrderController;
+
+
+
+
+
+
 use Stancl\Tenancy\Middleware\InitializeTenancyByDomainOrSubdomain;
 
 // 登入/登出路由
-Route::get('/login', [LoginController::class, 'show'])->name('login');
-Route::post('/login', [LoginController::class, 'store']);
-Route::post('/logout', [LoginController::class, 'destroy'])->name('logout');
+
 
 Route::middleware('auth')->group(function () {
     // 儀表板 - 所有登入使用者皆可存取
-    Route::get('/', [DashboardController::class, 'index'])->name('dashboard');
 
-    // 使用者帳號設定
-    Route::get('/profile', [ProfileController::class, 'edit'])->name('profile.edit');
-    Route::patch('/profile', [ProfileController::class, 'update'])->name('profile.update');
-    Route::put('/profile/password', [ProfileController::class, 'updatePassword'])->name('profile.password');
 
-    // 類別管理 (用於商品對話框) - 需要商品權限
-    Route::middleware('permission:products.view')->group(function () {
-        Route::get('/categories', [CategoryController::class, 'index'])->name('categories.index');
-        Route::post('/categories', [CategoryController::class, 'store'])->middleware('permission:products.create')->name('categories.store');
-        Route::put('/categories/{category}', [CategoryController::class, 'update'])->middleware('permission:products.edit')->name('categories.update');
-        Route::delete('/categories/{category}', [CategoryController::class, 'destroy'])->middleware('permission:products.delete')->name('categories.destroy');
-    });
 
-    // 單位管理 - 需要商品權限
-    Route::middleware('permission:products.create|products.edit')->group(function () {
-        Route::post('/units', [UnitController::class, 'store'])->name('units.store');
-        Route::put('/units/{unit}', [UnitController::class, 'update'])->name('units.update');
-        Route::delete('/units/{unit}', [UnitController::class, 'destroy'])->name('units.destroy');
-    });
 
-    // 商品管理
-    Route::middleware('permission:products.view')->group(function () {
-        Route::get('/products', [ProductController::class, 'index'])->name('products.index');
-        Route::post('/products', [ProductController::class, 'store'])->middleware('permission:products.create')->name('products.store');
-        Route::put('/products/{product}', [ProductController::class, 'update'])->middleware('permission:products.edit')->name('products.update');
-        Route::delete('/products/{product}', [ProductController::class, 'destroy'])->middleware('permission:products.delete')->name('products.destroy');
-    });
 
-    // 廠商管理
-    Route::middleware('permission:vendors.view')->group(function () {
-        Route::get('/vendors', [VendorController::class, 'index'])->name('vendors.index');
-        Route::get('/vendors/{vendor}', [VendorController::class, 'show'])->name('vendors.show');
-        Route::post('/vendors', [VendorController::class, 'store'])->middleware('permission:vendors.create')->name('vendors.store');
-        Route::put('/vendors/{vendor}', [VendorController::class, 'update'])->middleware('permission:vendors.edit')->name('vendors.update');
-        Route::delete('/vendors/{vendor}', [VendorController::class, 'destroy'])->middleware('permission:vendors.delete')->name('vendors.destroy');
 
-        // 供貨商品相關路由
-        Route::post('/vendors/{vendor}/products', [VendorProductController::class, 'store'])->middleware('permission:vendors.edit')->name('vendors.products.store');
-        Route::put('/vendors/{vendor}/products/{product}', [VendorProductController::class, 'update'])->middleware('permission:vendors.edit')->name('vendors.products.update');
-        Route::delete('/vendors/{vendor}/products/{product}', [VendorProductController::class, 'destroy'])->middleware('permission:vendors.edit')->name('vendors.products.destroy');
-    });
 
-    // 倉庫管理
-    Route::middleware('permission:warehouses.view')->group(function () {
-        Route::get('/warehouses', [WarehouseController::class, 'index'])->name('warehouses.index');
-        Route::post('/warehouses', [WarehouseController::class, 'store'])->middleware('permission:warehouses.create')->name('warehouses.store');
-        Route::put('/warehouses/{warehouse}', [WarehouseController::class, 'update'])->middleware('permission:warehouses.edit')->name('warehouses.update');
-        Route::delete('/warehouses/{warehouse}', [WarehouseController::class, 'destroy'])->middleware('permission:warehouses.delete')->name('warehouses.destroy');
 
-        // 倉庫庫存管理 - 需要庫存權限
-        Route::middleware('permission:inventory.view')->group(function () {
-            Route::get('/warehouses/{warehouse}/inventory', [InventoryController::class, 'index'])->name('warehouses.inventory.index');
-            Route::get('/warehouses/{warehouse}/inventory-history', [InventoryController::class, 'history'])->name('warehouses.inventory.history');
-            
-            Route::middleware('permission:inventory.adjust')->group(function () {
-                Route::get('/warehouses/{warehouse}/inventory/create', [InventoryController::class, 'create'])->name('warehouses.inventory.create');
-                Route::post('/warehouses/{warehouse}/inventory', [InventoryController::class, 'store'])->name('warehouses.inventory.store');
-                Route::get('/warehouses/{warehouse}/inventory/{inventoryId}/edit', [InventoryController::class, 'edit'])->name('warehouses.inventory.edit');
-                Route::put('/warehouses/{warehouse}/inventory/{inventoryId}', [InventoryController::class, 'update'])->name('warehouses.inventory.update');
-                Route::delete('/warehouses/{warehouse}/inventory/{inventoryId}', [InventoryController::class, 'destroy'])->name('warehouses.inventory.destroy');
-            });
 
-            // API: 取得商品在特定倉庫的所有批號
-            Route::get('/api/warehouses/{warehouse}/inventory/batches/{productId}', [InventoryController::class, 'getBatches'])
-                ->name('api.warehouses.inventory.batches');
-        });
 
-        // 安全庫存設定
-        Route::middleware('permission:inventory.view')->group(function () {
-            Route::get('/warehouses/{warehouse}/safety-stock', [SafetyStockController::class, 'index'])->name('warehouses.safety-stock.index');
-            Route::middleware('permission:inventory.safety_stock')->group(function () {
-                Route::post('/warehouses/{warehouse}/safety-stock', [SafetyStockController::class, 'store'])->name('warehouses.safety-stock.store');
-                Route::put('/warehouses/{warehouse}/safety-stock/{safetyStock}', [SafetyStockController::class, 'update'])->name('warehouses.safety-stock.update');
-                Route::delete('/warehouses/{warehouse}/safety-stock/{safetyStock}', [SafetyStockController::class, 'destroy'])->name('warehouses.safety-stock.destroy');
-            });
-        });
-    });
 
-    // 採購單管理
-    Route::middleware('permission:purchase_orders.view')->group(function () {
-        Route::get('/purchase-orders', [PurchaseOrderController::class, 'index'])->name('purchase-orders.index');
-        
-        Route::middleware('permission:purchase_orders.create')->group(function () {
-            Route::get('/purchase-orders/create', [PurchaseOrderController::class, 'create'])->name('purchase-orders.create');
-            Route::post('/purchase-orders', [PurchaseOrderController::class, 'store'])->name('purchase-orders.store');
-        });
 
-        Route::get('/purchase-orders/{id}', [PurchaseOrderController::class, 'show'])->name('purchase-orders.show');
-        
-        Route::get('/purchase-orders/{id}/edit', [PurchaseOrderController::class, 'edit'])->middleware('permission:purchase_orders.edit')->name('purchase-orders.edit');
-        Route::put('/purchase-orders/{id}', [PurchaseOrderController::class, 'update'])->middleware('permission:purchase_orders.edit')->name('purchase-orders.update');
-        Route::delete('/purchase-orders/{id}', [PurchaseOrderController::class, 'destroy'])->middleware('permission:purchase_orders.delete')->name('purchase-orders.destroy');
-    });
 
-    // 公共事業費管理 (TODO: 添加權限控制)
-        // 公共事業費
-        Route::middleware('permission:utility_fees.view')->group(function () {
-            Route::get('/utility-fees', [UtilityFeeController::class, 'index'])->name('utility-fees.index');
-        });
-        Route::middleware('permission:utility_fees.create')->group(function () {
-            Route::post('/utility-fees', [UtilityFeeController::class, 'store'])->name('utility-fees.store');
-        });
-        Route::middleware('permission:utility_fees.edit')->group(function () {
-            Route::put('/utility-fees/{utility_fee}', [UtilityFeeController::class, 'update'])->name('utility-fees.update');
-        });
-        Route::middleware('permission:utility_fees.delete')->group(function () {
-            Route::delete('/utility-fees/{utility_fee}', [UtilityFeeController::class, 'destroy'])->name('utility-fees.destroy');
-        });
 
-    // 撥補單 (在庫存調撥時使用)
-    Route::middleware('permission:inventory.transfer')->group(function () {
-        Route::post('/transfer-orders', [TransferOrderController::class, 'store'])->name('transfer-orders.store');
-    });
-    Route::get('/api/warehouses/{warehouse}/inventories', [TransferOrderController::class, 'getWarehouseInventories'])
-        ->middleware('permission:inventory.view')
-        ->name('api.warehouses.inventories');
 
-    // 系統管理
-    Route::middleware('permission:accounting.view')->prefix('accounting-report')->group(function () {
-        Route::get('/', [AccountingReportController::class, 'index'])->name('accounting.report');
-        Route::get('/export', [AccountingReportController::class, 'export'])
-            ->middleware('permission:accounting.export')
-            ->name('accounting.export');
-    });
 
-    // 生產管理
-    Route::middleware('permission:production_orders.view')->group(function () {
-        Route::get('/production-orders', [ProductionOrderController::class, 'index'])->name('production-orders.index');
-        
-        Route::middleware('permission:production_orders.create')->group(function () {
-            Route::get('/production-orders/create', [ProductionOrderController::class, 'create'])->name('production-orders.create');
-            Route::post('/production-orders', [ProductionOrderController::class, 'store'])->name('production-orders.store');
-        });
-        
-        Route::get('/production-orders/{productionOrder}', [ProductionOrderController::class, 'show'])->name('production-orders.show');
-        
-        Route::middleware('permission:production_orders.edit')->group(function () {
-            Route::get('/production-orders/{productionOrder}/edit', [ProductionOrderController::class, 'edit'])->name('production-orders.edit');
-            Route::put('/production-orders/{productionOrder}', [ProductionOrderController::class, 'update'])->name('production-orders.update');
-        });
-    });
 
-    // 生產管理 API
-    Route::get('/api/production/warehouses/{warehouse}/inventories', [ProductionOrderController::class, 'getWarehouseInventories'])
-        ->middleware('permission:production_orders.create')
-        ->name('api.production.warehouses.inventories');
 
-    // 系統管理
-    Route::prefix('admin')->group(function () {
-        Route::middleware('permission:roles.view')->group(function () {
-            Route::get('/roles', [RoleController::class, 'index'])->name('roles.index');
-            Route::middleware('permission:roles.create')->group(function () {
-                Route::get('/roles/create', [RoleController::class, 'create'])->name('roles.create');
-                Route::post('/roles', [RoleController::class, 'store'])->name('roles.store');
-            });
-            Route::get('/roles/{role}/edit', [RoleController::class, 'edit'])->middleware('permission:roles.edit')->name('roles.edit');
-            Route::put('/roles/{role}', [RoleController::class, 'update'])->middleware('permission:roles.edit')->name('roles.update');
-            Route::delete('/roles/{role}', [RoleController::class, 'destroy'])->middleware('permission:roles.delete')->name('roles.destroy');
-        });
-        
-        Route::middleware('permission:users.view')->group(function () {
-            Route::get('/users', [UserController::class, 'index'])->name('users.index');
-            Route::middleware('permission:users.create')->group(function () {
-                Route::get('/users/create', [UserController::class, 'create'])->name('users.create');
-                Route::post('/users', [UserController::class, 'store'])->name('users.store');
-            });
-            Route::get('/users/{user}/edit', [UserController::class, 'edit'])->middleware('permission:users.edit')->name('users.edit');
-            Route::put('/users/{user}', [UserController::class, 'update'])->middleware('permission:users.edit')->name('users.update');
-            Route::delete('/users/{user}', [UserController::class, 'destroy'])->middleware('permission:users.delete')->name('users.destroy');
-        });
 
-        Route::middleware('permission:system.view_logs')->group(function () {
-            Route::get('/activity-logs', [ActivityLogController::class, 'index'])->name('activity-logs.index');
-        });
-
-    });
 
 }); // End of auth middleware group