diff --git a/app/Http/Controllers/Admin/Manage/OrderController.php b/app/Http/Controllers/Admin/Manage/OrderController.php
index 7867e3b..b30d6ca 100644
--- a/app/Http/Controllers/Admin/Manage/OrderController.php
+++ b/app/Http/Controllers/Admin/Manage/OrderController.php
@@ -79,7 +79,11 @@ public function store(OrderRequest $request): RedirectResponse
                         'price_type' => $item['price_type'],
                     ]);
 
-                    Product::find($item['product_id'])->decrement('stock', $item['qty']);
+                    $product = Product::find($item['product_id']);
+                    if ($product->stock < $item['qty']) {
+                        throw new \InvalidArgumentException("Stok produk {$product->name} tidak mencukupi. Sisa stok: {$product->stock}");
+                    }
+                    $product->decrement('stock', $item['qty']);
                 }
 
                 OrderItem::where('user_id', auth()->id())
@@ -88,6 +92,8 @@ public function store(OrderRequest $request): RedirectResponse
             });
 
             return redirect()->route('order.index')->with('success', 'Pesanan berhasil disimpan');
+        } catch (\InvalidArgumentException $e) {
+            return redirect()->back()->withInput()->with('error', $e->getMessage());
         } catch (\Throwable $e) {
             LogHelper::logException($e, 'Failed to store order', [
                 'customer_name' => $validated['customer_name'],
@@ -166,11 +172,17 @@ public function update(OrderRequest $request, Order $order): RedirectResponse
                         'price_type' => $item['price_type'],
                     ]);
 
-                    Product::find($item['product_id'])->decrement('stock', $item['qty']);
+                    $product = Product::find($item['product_id']);
+                    if ($product->stock < $item['qty']) {
+                        throw new \InvalidArgumentException("Stok produk {$product->name} tidak mencukupi. Sisa stok: {$product->stock}");
+                    }
+                    $product->decrement('stock', $item['qty']);
                 }
             });
 
             return redirect()->route('order.index')->with('success', 'Pesanan berhasil diperbarui');
+        } catch (\InvalidArgumentException $e) {
+            return redirect()->back()->withInput()->with('error', $e->getMessage());
         } catch (\Throwable $e) {
             LogHelper::logException($e, 'Failed to update order', [
                 'order_id' => $order->id,
diff --git a/app/Http/Controllers/Admin/Manage/PurchaseController.php b/app/Http/Controllers/Admin/Manage/PurchaseController.php
index b3aafc1..9647a4d 100644
--- a/app/Http/Controllers/Admin/Manage/PurchaseController.php
+++ b/app/Http/Controllers/Admin/Manage/PurchaseController.php
@@ -106,6 +106,9 @@ public function update(PurchaseRequest $request, Purchase $purchase): RedirectRe
                 ]);
 
                 foreach ($purchase->items as $item) {
+                    if ($item->product->stock < $item->quantity) {
+                        throw new \InvalidArgumentException("Stok produk {$item->product->name} tidak mencukupi untuk dibatalkan. Sisa stok: {$item->product->stock}");
+                    }
                     $item->product->decrement('stock', $item->quantity);
                 }
 
@@ -125,6 +128,8 @@ public function update(PurchaseRequest $request, Purchase $purchase): RedirectRe
             });
 
             return redirect()->route('purchase.index')->with('success', 'Data berhasil diperbarui');
+        } catch (\InvalidArgumentException $e) {
+            return redirect()->back()->withInput()->with('error', $e->getMessage());
         } catch (\Throwable $e) {
             LogHelper::logException($e, 'Failed to update purchase', [
                 'purchase_id' => $purchase->id,
@@ -143,12 +148,17 @@ public function destroy(Purchase $purchase): RedirectResponse
         try {
             DB::transaction(function () use ($purchase) {
                 foreach ($purchase->items as $item) {
+                    if ($item->product->stock < $item->quantity) {
+                        throw new \InvalidArgumentException("Stok produk {$item->product->name} tidak mencukupi untuk dihapus. Sisa stok: {$item->product->stock}");
+                    }
                     $item->product->decrement('stock', $item->quantity);
                 }
                 $purchase->delete();
             });
 
             return redirect()->back()->with('success', 'Data berhasil dihapus');
+        } catch (\InvalidArgumentException $e) {
+            return redirect()->back()->with('error', $e->getMessage());
         } catch (\Throwable $e) {
             LogHelper::logException($e, 'Failed to delete purchase', [
                 'purchase_id' => $purchase->id,
@@ -164,9 +174,12 @@ public function bulkDestroy(Request $request): RedirectResponse
 
         try {
             DB::transaction(function () use ($ids) {
-                $purchases = Purchase::with('items')->whereIn('id', $ids)->get();
+                $purchases = Purchase::with('items.product')->whereIn('id', $ids)->get();
                 foreach ($purchases as $purchase) {
                     foreach ($purchase->items as $item) {
+                        if ($item->product->stock < $item->quantity) {
+                            throw new \InvalidArgumentException("Stok produk {$item->product->name} tidak mencukupi untuk dihapus. Sisa stok: {$item->product->stock}");
+                        }
                         $item->product->decrement('stock', $item->quantity);
                     }
                     $purchase->delete();
@@ -174,6 +187,8 @@ public function bulkDestroy(Request $request): RedirectResponse
             });
 
             return redirect()->back()->with('success', 'Data terpilih berhasil dihapus');
+        } catch (\InvalidArgumentException $e) {
+            return redirect()->back()->with('error', $e->getMessage());
         } catch (\Throwable $e) {
             LogHelper::logException($e, 'Failed to bulk delete purchases', [
                 'ids' => $ids,
diff --git a/database/migrations/2026_04_16_082802_create_products_table.php b/database/migrations/2026_04_16_082802_create_products_table.php
index 5c1b7b0..cbf2ea0 100644
--- a/database/migrations/2026_04_16_082802_create_products_table.php
+++ b/database/migrations/2026_04_16_082802_create_products_table.php
@@ -16,7 +16,7 @@ public function up(): void
             $table->string('name', 100);
             $table->string('slug', 100);
             $table->text('description')->nullable();
-            $table->integer('stock')->default(0);
+            $table->unsignedInteger('stock')->default(0);
             $table->boolean('is_active')->default(true);
             $table->timestamp('created_at')->useCurrent();
             $table->timestamp('updated_at')->nullable()->useCurrentOnUpdate();
diff --git a/resources/js/pages/admin/manage/order/create.tsx b/resources/js/pages/admin/manage/order/create.tsx
index 340c1f0..3c458a3 100644
--- a/resources/js/pages/admin/manage/order/create.tsx
+++ b/resources/js/pages/admin/manage/order/create.tsx
@@ -180,7 +180,12 @@ return;
 
         post(orderRoutes.store().url, {
             onSuccess: (response: any) => {
-                toast.success(response.props.flash.success);
+                const flash = response.props.flash;
+                if (flash?.error) {
+                    toast.error(flash.error);
+                } else if (flash?.success) {
+                    toast.success(flash.success);
+                }
             },
         });
     };
diff --git a/resources/js/pages/admin/manage/order/edit.tsx b/resources/js/pages/admin/manage/order/edit.tsx
index 96a59e3..26c2a9b 100644
--- a/resources/js/pages/admin/manage/order/edit.tsx
+++ b/resources/js/pages/admin/manage/order/edit.tsx
@@ -195,7 +195,12 @@ return;
 
         patch(orderRoutes.update(order.id).url, {
             onSuccess: (response: any) => {
-                toast.success(response.props.flash.success);
+                const flash = response.props.flash;
+                if (flash?.error) {
+                    toast.error(flash.error);
+                } else if (flash?.success) {
+                    toast.success(flash.success);
+                }
             },
         });
     };
diff --git a/resources/js/pages/admin/manage/purchase/create.tsx b/resources/js/pages/admin/manage/purchase/create.tsx
index 625eaf3..f33ffa0 100644
--- a/resources/js/pages/admin/manage/purchase/create.tsx
+++ b/resources/js/pages/admin/manage/purchase/create.tsx
@@ -165,7 +165,12 @@ return;
 
         post(purchaseRoutes.store().url, {
             onSuccess: (response: any) => {
-                toast.success(response.props.flash.success);
+                const flash = response.props.flash;
+                if (flash?.error) {
+                    toast.error(flash.error);
+                } else if (flash?.success) {
+                    toast.success(flash.success);
+                }
             },
         });
     };
diff --git a/resources/js/pages/admin/manage/purchase/edit.tsx b/resources/js/pages/admin/manage/purchase/edit.tsx
index d89ea3b..92fe580 100644
--- a/resources/js/pages/admin/manage/purchase/edit.tsx
+++ b/resources/js/pages/admin/manage/purchase/edit.tsx
@@ -170,7 +170,12 @@ export default function PurchaseEdit({ purchase, products }: { purchase: Purchas
 
         patch(purchaseRoutes.update(purchase.id).url, {
             onSuccess: (response: any) => {
-                toast.success(response.props.flash.success);
+                const flash = response.props.flash;
+                if (flash?.error) {
+                    toast.error(flash.error);
+                } else if (flash?.success) {
+                    toast.success(flash.success);
+                }
             },
         });
     };
diff --git a/resources/js/pages/admin/manage/purchase/hooks/use-purchase-index.ts b/resources/js/pages/admin/manage/purchase/hooks/use-purchase-index.ts
index 1e67fa9..80763d3 100644
--- a/resources/js/pages/admin/manage/purchase/hooks/use-purchase-index.ts
+++ b/resources/js/pages/admin/manage/purchase/hooks/use-purchase-index.ts
@@ -20,7 +20,12 @@ export function usePurchaseIndex() {
         if (purchaseToDelete) {
             router.delete(purchaseRoutes.destroy(purchaseToDelete.id).url, {
                 onSuccess: (response: any) => {
-                    toast.success(response.props.flash.success);
+                    const flash = response.props.flash;
+                    if (flash?.error) {
+                        toast.error(flash.error);
+                    } else if (flash?.success) {
+                        toast.success(flash.success);
+                    }
                     setIsDeleteDialogOpen(false);
                     setPurchaseToDelete(null);
                     setRowSelection({});
@@ -35,7 +40,12 @@ export function usePurchaseIndex() {
             _method: 'DELETE'
         }, {
             onSuccess: (response: any) => {
-                toast.success(response.props.flash.success);
+                const flash = response.props.flash;
+                if (flash?.error) {
+                    toast.error(flash.error);
+                } else if (flash?.success) {
+                    toast.success(flash.success);
+                }
                 setIsBulkDeleteDialogOpen(false);
                 setRowsToDelete([]);
                 setRowSelection({});
diff --git a/resources/js/pages/admin/master/product/create.tsx b/resources/js/pages/admin/master/product/create.tsx
index a071e6a..c350916 100644
--- a/resources/js/pages/admin/master/product/create.tsx
+++ b/resources/js/pages/admin/master/product/create.tsx
@@ -113,7 +113,12 @@ export default function ProductCreate({ categories }: { categories: Category[] }
         post(productRoutes.store().url, {
             forceFormData: true,
             onSuccess: (response: any) => {
-                toast.success(response.props.flash.success);
+                const flash = response.props.flash;
+                if (flash?.error) {
+                    toast.error(flash.error);
+                } else if (flash?.success) {
+                    toast.success(flash.success);
+                }
             },
         });
     };
diff --git a/resources/js/pages/admin/master/product/edit.tsx b/resources/js/pages/admin/master/product/edit.tsx
index e9caff2..93e957e 100644
--- a/resources/js/pages/admin/master/product/edit.tsx
+++ b/resources/js/pages/admin/master/product/edit.tsx
@@ -165,7 +165,12 @@ export default function ProductEdit({ product, categories }: { product: Product,
         post(productRoutes.update(product.id).url, {
             forceFormData: true,
             onSuccess: (response: any) => {
-                toast.success(response.props.flash.success);
+                const flash = response.props.flash;
+                if (flash?.error) {
+                    toast.error(flash.error);
+                } else if (flash?.success) {
+                    toast.success(flash.success);
+                }
             },
         });
     };
diff --git a/resources/js/pages/admin/master/product/hooks/use-product-index.ts b/resources/js/pages/admin/master/product/hooks/use-product-index.ts
index 7a8870a..df77e1f 100644
--- a/resources/js/pages/admin/master/product/hooks/use-product-index.ts
+++ b/resources/js/pages/admin/master/product/hooks/use-product-index.ts
@@ -21,7 +21,12 @@ export function useProductIndex() {
         if (productToDelete) {
             router.delete(productRoutes.destroy(productToDelete.id).url, {
                 onSuccess: (response: any) => {
-                    toast.success(response.props.flash.success);
+                    const flash = response.props.flash;
+                    if (flash?.error) {
+                        toast.error(flash.error);
+                    } else if (flash?.success) {
+                        toast.success(flash.success);
+                    }
                     setIsDeleteDialogOpen(false);
                     setProductToDelete(null);
                     setRowSelection({});
@@ -36,7 +41,12 @@ export function useProductIndex() {
             _method: 'DELETE'
         }, {
             onSuccess: (response: any) => {
-                toast.success(response.props.flash.success);
+                const flash = response.props.flash;
+                if (flash?.error) {
+                    toast.error(flash.error);
+                } else if (flash?.success) {
+                    toast.success(flash.success);
+                }
                 setIsBulkDeleteDialogOpen(false);
                 setRowsToDelete([]);
                 setRowSelection({});
@@ -48,7 +58,14 @@ export function useProductIndex() {
         router.patch(productRoutes.toggleStatus(id).url, {}, {
             preserveState: true,
             preserveScroll: true,
-            onSuccess: (response: any) => toast.success(response.props.flash.success),
+            onSuccess: (response: any) => {
+                const flash = response.props.flash;
+                if (flash?.error) {
+                    toast.error(flash.error);
+                } else if (flash?.success) {
+                    toast.success(flash.success);
+                }
+            },
         });
     };
 
diff --git a/resources/js/pages/admin/master/user/create.tsx b/resources/js/pages/admin/master/user/create.tsx
index 1abdf67..2fd34d3 100644
--- a/resources/js/pages/admin/master/user/create.tsx
+++ b/resources/js/pages/admin/master/user/create.tsx
@@ -50,7 +50,12 @@ export default function UserCreate({ roles }: { roles: any[] }) {
         e.preventDefault();
         post(userRoutes.store().url, {
             onSuccess: (response: any) => {
-                toast.success(response.props.flash.success);
+                const flash = response.props.flash;
+                if (flash?.error) {
+                    toast.error(flash.error);
+                } else if (flash?.success) {
+                    toast.success(flash.success);
+                }
             },
         });
     };
diff --git a/resources/js/pages/admin/master/user/edit.tsx b/resources/js/pages/admin/master/user/edit.tsx
index c1948d0..db57385 100644
--- a/resources/js/pages/admin/master/user/edit.tsx
+++ b/resources/js/pages/admin/master/user/edit.tsx
@@ -51,7 +51,12 @@ export default function UserEdit({ user, roles }: { user: any, roles: any[] }) {
         e.preventDefault();
         post(userRoutes.update(user.id).url, {
             onSuccess: (response: any) => {
-                toast.success(response.props.flash.success);
+                const flash = response.props.flash;
+                if (flash?.error) {
+                    toast.error(flash.error);
+                } else if (flash?.success) {
+                    toast.success(flash.success);
+                }
             },
         });
     };
diff --git a/resources/js/pages/admin/master/user/hooks/use-user-index.ts b/resources/js/pages/admin/master/user/hooks/use-user-index.ts
index 46abec8..b04ca09 100644
--- a/resources/js/pages/admin/master/user/hooks/use-user-index.ts
+++ b/resources/js/pages/admin/master/user/hooks/use-user-index.ts
@@ -22,7 +22,12 @@ export function useUserIndex() {
         if (userToReset) {
             router.patch(userRoutes.resetPassword(userToReset.id).url, {}, {
                 onSuccess: (response: any) => {
-                    toast.success(response.props.flash.success);
+                    const flash = response.props.flash;
+                    if (flash?.error) {
+                        toast.error(flash.error);
+                    } else if (flash?.success) {
+                        toast.success(flash.success);
+                    }
                     setIsResetPasswordOpen(false);
                     setUserToReset(null);
                 },
@@ -39,7 +44,12 @@ export function useUserIndex() {
         if (userToDelete) {
             router.delete(userRoutes.destroy(userToDelete.id).url, {
                 onSuccess: (response: any) => {
-                    toast.success(response.props.flash.success);
+                    const flash = response.props.flash;
+                    if (flash?.error) {
+                        toast.error(flash.error);
+                    } else if (flash?.success) {
+                        toast.success(flash.success);
+                    }
                     setIsDeleteDialogOpen(false);
                     setUserToDelete(null);
                     setRowSelection({});
@@ -54,7 +64,12 @@ export function useUserIndex() {
             _method: 'DELETE'
         }, {
             onSuccess: (response: any) => {
-                toast.success(response.props.flash.success);
+                const flash = response.props.flash;
+                if (flash?.error) {
+                    toast.error(flash.error);
+                } else if (flash?.success) {
+                    toast.success(flash.success);
+                }
                 setIsBulkDeleteDialogOpen(false);
                 setRowsToDelete([]);
                 setRowSelection({});
@@ -67,7 +82,12 @@ export function useUserIndex() {
             preserveState: true,
             preserveScroll: true,
             onSuccess: (response: any) => {
-                toast.success(response.props.flash.success);
+                const flash = response.props.flash;
+                if (flash?.error) {
+                    toast.error(flash.error);
+                } else if (flash?.success) {
+                    toast.success(flash.success);
+                }
             },
         });
     };
diff --git a/resources/js/pages/admin/system/role/create.tsx b/resources/js/pages/admin/system/role/create.tsx
index e06d458..5c91d4a 100644
--- a/resources/js/pages/admin/system/role/create.tsx
+++ b/resources/js/pages/admin/system/role/create.tsx
@@ -30,7 +30,12 @@ export default function RoleCreate({
         e.preventDefault();
         post(roleRoutes.store().url, {
             onSuccess: (response: any) => {
-                toast.success(response.props.flash.success);
+                const flash = response.props.flash;
+                if (flash?.error) {
+                    toast.error(flash.error);
+                } else if (flash?.success) {
+                    toast.success(flash.success);
+                }
             },
         });
     };
diff --git a/resources/js/pages/admin/system/role/edit.tsx b/resources/js/pages/admin/system/role/edit.tsx
index 4f51445..a0f8e11 100644
--- a/resources/js/pages/admin/system/role/edit.tsx
+++ b/resources/js/pages/admin/system/role/edit.tsx
@@ -32,7 +32,12 @@ export default function RoleEdit({
         e.preventDefault();
         put(roleRoutes.update(role.id).url, {
             onSuccess: (response: any) => {
-                toast.success(response.props.flash.success);
+                const flash = response.props.flash;
+                if (flash?.error) {
+                    toast.error(flash.error);
+                } else if (flash?.success) {
+                    toast.success(flash.success);
+                }
             },
         });
     };
diff --git a/resources/js/pages/admin/system/role/hooks/use-role-index.ts b/resources/js/pages/admin/system/role/hooks/use-role-index.ts
index 44fcd66..ccce0a5 100644
--- a/resources/js/pages/admin/system/role/hooks/use-role-index.ts
+++ b/resources/js/pages/admin/system/role/hooks/use-role-index.ts
@@ -20,7 +20,12 @@ export function useRoleIndex() {
         if (roleToDelete) {
             router.delete(roleRoutes.destroy(roleToDelete.id).url, {
                 onSuccess: (response: any) => {
-                    toast.success(response.props.flash.success);
+                    const flash = response.props.flash;
+                    if (flash?.error) {
+                        toast.error(flash.error);
+                    } else if (flash?.success) {
+                        toast.success(flash.success);
+                    }
                     setIsDeleteDialogOpen(false);
                     setRoleToDelete(null);
                     setRowSelection({});
@@ -35,7 +40,12 @@ export function useRoleIndex() {
             _method: 'DELETE'
         }, {
             onSuccess: (response: any) => {
-                toast.success(response.props.flash.success);
+                const flash = response.props.flash;
+                if (flash?.error) {
+                    toast.error(flash.error);
+                } else if (flash?.success) {
+                    toast.success(flash.success);
+                }
                 setIsBulkDeleteDialogOpen(false);
                 setRowsToDelete([]);
                 setRowSelection({});