diff --git a/backend/internal/handler/payment_webhook_handler.go b/backend/internal/handler/payment_webhook_handler.go
index 78a7ba12e8..6b6f129e46 100644
--- a/backend/internal/handler/payment_webhook_handler.go
+++ b/backend/internal/handler/payment_webhook_handler.go
@@ -83,7 +83,12 @@ func (h *PaymentWebhookHandler) handleNotify(c *gin.Context, providerKey string)
 
 	notification, err := provider.VerifyNotification(c.Request.Context(), rawBody, headers)
 	if err != nil {
-		slog.Error("[Payment Webhook] verify failed", "provider", providerKey, "error", err, "method", c.Request.Method, "rawBody", rawBody)
+		truncatedBody := rawBody
+		if len(truncatedBody) > 200 {
+			truncatedBody = truncatedBody[:200] + "...(truncated)"
+		}
+		slog.Error("[Payment Webhook] verify failed", "provider", providerKey, "error", err, "method", c.Request.Method, "bodyLen", len(rawBody))
+		slog.Debug("[Payment Webhook] verify failed body", "provider", providerKey, "rawBody", truncatedBody)
 		c.String(http.StatusBadRequest, "verify failed")
 		return
 	}
diff --git a/backend/internal/payment/provider/easypay.go b/backend/internal/payment/provider/easypay.go
index 07b9954d03..973a664084 100644
--- a/backend/internal/payment/provider/easypay.go
+++ b/backend/internal/payment/provider/easypay.go
@@ -21,9 +21,10 @@ import (
 
 // EasyPay constants.
 const (
-	easypayCodeSuccess = 1
-	easypayStatusPaid  = 1
-	easypayHTTPTimeout = 10 * time.Second
+	easypayCodeSuccess     = 1
+	easypayStatusPaid      = 1
+	easypayHTTPTimeout     = 10 * time.Second
+	maxEasypayResponseSize = 1 << 20 // 1MB
 )
 
 // EasyPay implements payment.Provider for the EasyPay aggregation platform.
@@ -169,7 +170,7 @@ func (e *EasyPay) VerifyNotification(_ context.Context, rawBody string, _ map[st
 	}
 	params := make(map[string]string)
 	for k := range values {
-		params[k] = fullyDecodeURL(values.Get(k))
+		params[k] = decodeURLValue(values.Get(k))
 	}
 	sign := params["sign"]
 	if sign == "" {
@@ -239,7 +240,7 @@ func (e *EasyPay) post(ctx context.Context, endpoint string, params map[string]s
 		return nil, err
 	}
 	defer func() { _ = resp.Body.Close() }()
-	return io.ReadAll(resp.Body)
+	return io.ReadAll(io.LimitReader(resp.Body, maxEasypayResponseSize))
 }
 
 func easyPaySign(params map[string]string, pkey string) string {
@@ -267,14 +268,11 @@ func easyPayVerifySign(params map[string]string, pkey string, sign string) bool
 	return hmac.Equal([]byte(easyPaySign(params, pkey)), []byte(sign))
 }
 
-// fullyDecodeURL repeatedly URL-decodes a string until stable.
-// Handles double (or multi) encoding caused by upstream proxies.
-func fullyDecodeURL(s string) string {
-	for {
-		decoded, err := url.QueryUnescape(s)
-		if err != nil || decoded == s {
-			return s
-		}
-		s = decoded
+// decodeURLValue URL-decodes a string once.
+func decodeURLValue(s string) string {
+	decoded, err := url.QueryUnescape(s)
+	if err != nil {
+		return s
 	}
+	return decoded
 }
diff --git a/backend/internal/payment/wire.go b/backend/internal/payment/wire.go
index f3dc0abf0d..880c55456d 100644
--- a/backend/internal/payment/wire.go
+++ b/backend/internal/payment/wire.go
@@ -2,6 +2,7 @@ package payment
 
 import (
 	"encoding/hex"
+	"log/slog"
 
 	dbent "github.com/Wei-Shaw/sub2api/ent"
 	"github.com/Wei-Shaw/sub2api/internal/config"
@@ -14,7 +15,18 @@ type EncryptionKey []byte
 
 // ProvideEncryptionKey derives the payment encryption key from the TOTP encryption key in config.
 func ProvideEncryptionKey(cfg *config.Config) EncryptionKey {
-	key, _ := hex.DecodeString(cfg.Totp.EncryptionKey)
+	if cfg.Totp.EncryptionKey == "" {
+		return nil
+	}
+	key, err := hex.DecodeString(cfg.Totp.EncryptionKey)
+	if err != nil {
+		slog.Error("invalid payment encryption key", "error", err)
+		return nil
+	}
+	if len(key) != 32 {
+		slog.Error("payment encryption key must be 32 bytes", "got", len(key))
+		return nil
+	}
 	return EncryptionKey(key)
 }
 
diff --git a/backend/internal/service/payment_config_service.go b/backend/internal/service/payment_config_service.go
index 91e90967c1..de77c30b9e 100644
--- a/backend/internal/service/payment_config_service.go
+++ b/backend/internal/service/payment_config_service.go
@@ -343,6 +343,7 @@ type ProviderInstanceResponse struct {
 	Enabled        bool              `json:"enabled"`
 	RefundEnabled  bool              `json:"refund_enabled"`
 	SortOrder      int               `json:"sort_order"`
+	PaymentMode    string            `json:"payment_mode"`
 }
 
 // ListProviderInstancesWithConfig returns provider instances with decrypted
@@ -359,6 +360,7 @@ func (s *PaymentConfigService) ListProviderInstancesWithConfig(ctx context.Conte
 			ID: int64(inst.ID), ProviderKey: inst.ProviderKey, Name: inst.Name,
 			SupportedTypes: splitTypes(inst.SupportedTypes), Limits: inst.Limits,
 			Enabled: inst.Enabled, RefundEnabled: inst.RefundEnabled, SortOrder: inst.SortOrder,
+			PaymentMode: inst.PaymentMode,
 		}
 		resp.Config = s.decryptAndMaskConfig(inst.Config)
 		result = append(result, resp)
diff --git a/backend/internal/service/payment_service.go b/backend/internal/service/payment_service.go
index 33b6b75b70..824846213d 100644
--- a/backend/internal/service/payment_service.go
+++ b/backend/internal/service/payment_service.go
@@ -147,7 +147,7 @@ type TopUserStat struct {
 
 type PaymentService struct {
 	providerMu      sync.Mutex
-	providerOnce    sync.Once
+	providersLoaded bool
 	entClient       *dbent.Client
 	registry        *payment.Registry
 	loadBalancer    payment.LoadBalancer
@@ -200,7 +200,9 @@ func (s *PaymentService) CreateOrder(ctx context.Context, req CreateOrderRequest
 	}
 	resp, err := s.invokeProvider(ctx, order, req, cfg, payAmountStr, payAmount, plan)
 	if err != nil {
-		_ = s.entClient.PaymentOrder.DeleteOneID(order.ID).Exec(ctx)
+		_, _ = s.entClient.PaymentOrder.UpdateOneID(order.ID).
+			SetStatus(OrderStatusFailed).
+			Save(ctx)
 		return nil, err
 	}
 	return resp, nil
@@ -566,15 +568,40 @@ func (s *PaymentService) confirmPayment(ctx context.Context, oid int64, tradeNo
 }
 
 func (s *PaymentService) toPaid(ctx context.Context, o *dbent.PaymentOrder, tradeNo string, paid float64, pk string) error {
+	previousStatus := o.Status
 	now := time.Now()
 	grace := now.Add(-paymentGraceMinutes * time.Minute)
-	c, err := s.entClient.PaymentOrder.Update().Where(paymentorder.IDEQ(o.ID), paymentorder.Or(paymentorder.StatusEQ(OrderStatusPending), paymentorder.And(paymentorder.StatusEQ(OrderStatusExpired), paymentorder.UpdatedAtGTE(grace)))).SetStatus(OrderStatusPaid).SetPayAmount(paid).SetPaymentTradeNo(tradeNo).SetPaidAt(now).ClearFailedAt().ClearFailedReason().Save(ctx)
+	c, err := s.entClient.PaymentOrder.Update().Where(
+		paymentorder.IDEQ(o.ID),
+		paymentorder.Or(
+			paymentorder.StatusEQ(OrderStatusPending),
+			paymentorder.StatusEQ(OrderStatusCancelled),
+			paymentorder.And(
+				paymentorder.StatusEQ(OrderStatusExpired),
+				paymentorder.UpdatedAtGTE(grace),
+			),
+		),
+	).SetStatus(OrderStatusPaid).SetPayAmount(paid).SetPaymentTradeNo(tradeNo).SetPaidAt(now).ClearFailedAt().ClearFailedReason().Save(ctx)
 	if err != nil {
 		return fmt.Errorf("update to PAID: %w", err)
 	}
 	if c == 0 {
 		return s.alreadyProcessed(ctx, o)
 	}
+	if previousStatus == OrderStatusCancelled || previousStatus == OrderStatusExpired {
+		slog.Info("order recovered from webhook payment success",
+			"orderID", o.ID,
+			"previousStatus", previousStatus,
+			"tradeNo", tradeNo,
+			"provider", pk,
+		)
+		s.writeAuditLog(ctx, o.ID, "ORDER_RECOVERED", pk, map[string]any{
+			"previous_status": previousStatus,
+			"tradeNo":         tradeNo,
+			"paidAmount":      paid,
+			"reason":          "webhook payment success received after order " + previousStatus,
+		})
+	}
 	s.writeAuditLog(ctx, o.ID, "ORDER_PAID", pk, map[string]any{"tradeNo": tradeNo, "paidAmount": paid})
 	return s.executeFulfillment(ctx, o.ID)
 }
@@ -591,6 +618,18 @@ func (s *PaymentService) alreadyProcessed(ctx context.Context, o *dbent.PaymentO
 		return s.executeFulfillment(ctx, o.ID)
 	case OrderStatusPaid, OrderStatusRecharging:
 		return fmt.Errorf("order %d is being processed", o.ID)
+	case OrderStatusExpired:
+		slog.Warn("webhook payment success for expired order beyond grace period",
+			"orderID", o.ID,
+			"status", cur.Status,
+			"updatedAt", cur.UpdatedAt,
+		)
+		s.writeAuditLog(ctx, o.ID, "PAYMENT_AFTER_EXPIRY", "system", map[string]any{
+			"status":    cur.Status,
+			"updatedAt": cur.UpdatedAt,
+			"reason":    "payment arrived after expiry grace period",
+		})
+		return nil
 	default:
 		return nil
 	}
@@ -1174,9 +1213,12 @@ func (s *PaymentService) AdminListOrders(ctx context.Context, userID int64, p Or
 // It queries all enabled PaymentProviderInstance records, decrypts their config,
 // creates providers via provider.CreateProvider, and registers them.
 func (s *PaymentService) EnsureProviders(ctx context.Context) {
-	s.providerOnce.Do(func() {
+	s.providerMu.Lock()
+	defer s.providerMu.Unlock()
+	if !s.providersLoaded {
 		s.loadProviders(ctx)
-	})
+		s.providersLoaded = true
+	}
 }
 
 // RefreshProviders clears and re-registers all providers from the database.
@@ -1186,8 +1228,7 @@ func (s *PaymentService) RefreshProviders(ctx context.Context) {
 	defer s.providerMu.Unlock()
 	s.registry.Clear()
 	s.loadProviders(ctx)
-	s.providerOnce = sync.Once{} // reset so next EnsureProviders is a no-op until next Refresh
-	s.providerOnce.Do(func() {}) // mark as done since we just loaded
+	s.providersLoaded = true
 }
 
 func (s *PaymentService) loadProviders(ctx context.Context) {
diff --git a/frontend/src/components/payment/PaymentMethodSelector.vue b/frontend/src/components/payment/PaymentMethodSelector.vue
index 525e12b386..5e3f801cf7 100644
--- a/frontend/src/components/payment/PaymentMethodSelector.vue
+++ b/frontend/src/components/payment/PaymentMethodSelector.vue
@@ -39,6 +39,7 @@
 <script setup lang="ts">
 import { computed } from 'vue'
 import { useI18n } from 'vue-i18n'
+import { METHOD_ORDER } from './providerConfig'
 import alipayIcon from '@/assets/icons/alipay.svg'
 import wxpayIcon from '@/assets/icons/wxpay.svg'
 import stripeIcon from '@/assets/icons/stripe.svg'
@@ -60,9 +61,6 @@ const emit = defineEmits<{
 
 const { t } = useI18n()
 
-/** Fixed display order for payment methods */
-const METHOD_ORDER = ['alipay', 'wxpay', 'stripe']
-
 const METHOD_ICONS: Record<string, string> = {
   alipay: alipayIcon,
   wxpay: wxpayIcon,
@@ -70,9 +68,10 @@ const METHOD_ICONS: Record<string, string> = {
 }
 
 const sortedMethods = computed(() => {
+  const order: readonly string[] = METHOD_ORDER
   return [...props.methods].sort((a, b) => {
-    const ai = METHOD_ORDER.indexOf(a.type)
-    const bi = METHOD_ORDER.indexOf(b.type)
+    const ai = order.indexOf(a.type)
+    const bi = order.indexOf(b.type)
     return (ai === -1 ? 999 : ai) - (bi === -1 ? 999 : bi)
   })
 })
@@ -80,7 +79,7 @@ const sortedMethods = computed(() => {
 function methodIcon(type: string): string {
   if (type.includes('alipay')) return METHOD_ICONS.alipay
   if (type.includes('wxpay')) return METHOD_ICONS.wxpay
-  return METHOD_ICONS[type] || METHOD_ICONS.easypay
+  return METHOD_ICONS[type] || alipayIcon
 }
 
 function methodSelectedClass(type: string): string {
diff --git a/frontend/src/components/payment/PaymentProviderDialog.vue b/frontend/src/components/payment/PaymentProviderDialog.vue
index e6951896d2..79f00ed775 100644
--- a/frontend/src/components/payment/PaymentProviderDialog.vue
+++ b/frontend/src/components/payment/PaymentProviderDialog.vue
@@ -231,6 +231,8 @@ import {
   PROVIDER_SUPPORTED_TYPES,
   PROVIDER_CALLBACK_PATHS,
   WEBHOOK_PATHS,
+  PAYMENT_MODE_REDIRECT,
+  PAYMENT_MODE_API,
   getAvailableTypes,
   extractBaseUrl,
 } from './providerConfig'
@@ -267,7 +269,7 @@ const form = reactive({
   provider_key: 'easypay',
   supported_types: [] as string[],
   enabled: true,
-  payment_mode: 'api',
+  payment_mode: PAYMENT_MODE_API,
   refund_enabled: false,
 })
 const config = reactive<Record<string, string>>({})
@@ -287,8 +289,8 @@ const stripeWebhookUrl = computed(() =>
 const callbackPaths = computed(() => PROVIDER_CALLBACK_PATHS[form.provider_key] || null)
 
 const paymentModeOptions = computed(() => [
-  { value: 'redirect', label: t('admin.settings.payment.modeRedirect') },
-  { value: 'api', label: t('admin.settings.payment.modeQRCode') },
+  { value: PAYMENT_MODE_REDIRECT, label: t('admin.settings.payment.modeRedirect') },
+  { value: PAYMENT_MODE_API, label: t('admin.settings.payment.modeQRCode') },
 ])
 
 const availableTypes = computed(() => {
@@ -454,7 +456,7 @@ function reset(defaultKey: string) {
   form.provider_key = defaultKey
   form.supported_types = [...(PROVIDER_SUPPORTED_TYPES[defaultKey] || [])]
   form.enabled = true
-  form.payment_mode = defaultKey === 'easypay' ? 'api' : ''
+  form.payment_mode = defaultKey === 'easypay' ? PAYMENT_MODE_API : ''
   form.refund_enabled = false
   clearConfig()
   applyDefaults()
@@ -465,7 +467,7 @@ function loadProvider(provider: ProviderInstance) {
   form.provider_key = provider.provider_key
   form.supported_types = provider.supported_types
   form.enabled = provider.enabled
-  form.payment_mode = provider.payment_mode || 'api'
+  form.payment_mode = provider.payment_mode || PAYMENT_MODE_API
   form.refund_enabled = provider.refund_enabled
   clearConfig()
   // Pre-fill config from API response (non-sensitive in cleartext, sensitive masked as ••••••••)
diff --git a/frontend/src/components/payment/ProviderCard.vue b/frontend/src/components/payment/ProviderCard.vue
index b2e926f974..7a6cf2a9b9 100644
--- a/frontend/src/components/payment/ProviderCard.vue
+++ b/frontend/src/components/payment/ProviderCard.vue
@@ -68,6 +68,7 @@ import Icon from '@/components/icons/Icon.vue'
 import ToggleSwitch from './ToggleSwitch.vue'
 import type { ProviderInstance } from '@/types/payment'
 import type { TypeOption } from './providerConfig'
+import { PAYMENT_MODE_REDIRECT, PAYMENT_MODE_API } from './providerConfig'
 
 const PROVIDER_KEY_LABELS: Record<string, string> = {
   easypay: 'admin.settings.payment.providerEasypay',
@@ -94,8 +95,8 @@ const { t } = useI18n()
 const keyLabel = computed(() => t(PROVIDER_KEY_LABELS[props.provider.provider_key] || props.provider.provider_key))
 
 const modeLabel = computed(() => {
-  if (props.provider.payment_mode === 'redirect') return t('admin.settings.payment.modeRedirect')
-  if (props.provider.payment_mode === 'api') return t('admin.settings.payment.modeQRCode')
+  if (props.provider.payment_mode === PAYMENT_MODE_REDIRECT) return t('admin.settings.payment.modeRedirect')
+  if (props.provider.payment_mode === PAYMENT_MODE_API) return t('admin.settings.payment.modeQRCode')
   return ''
 })
 
diff --git a/frontend/src/components/payment/providerConfig.ts b/frontend/src/components/payment/providerConfig.ts
index 20201262a8..1fd3f49544 100644
--- a/frontend/src/components/payment/providerConfig.ts
+++ b/frontend/src/components/payment/providerConfig.ts
@@ -36,6 +36,13 @@ export const PROVIDER_SUPPORTED_TYPES: Record<string, string[]> = {
 /** Available payment modes for EasyPay providers. */
 export const EASYPAY_PAYMENT_MODES = ['redirect', 'api'] as const
 
+/** Fixed display order for user-facing payment methods */
+export const METHOD_ORDER = ['alipay', 'wxpay', 'stripe'] as const
+
+/** Payment mode constants */
+export const PAYMENT_MODE_REDIRECT = 'redirect'
+export const PAYMENT_MODE_API = 'api'
+
 /** Webhook paths for each provider (relative to origin). */
 export const WEBHOOK_PATHS: Record<string, string> = {
   easypay: '/api/v1/payment/webhook/easypay',
diff --git a/frontend/src/i18n/locales/en.ts b/frontend/src/i18n/locales/en.ts
index 426080b61c..6595a8ae46 100644
--- a/frontend/src/i18n/locales/en.ts
+++ b/frontend/src/i18n/locales/en.ts
@@ -5146,6 +5146,8 @@ export default {
     refundReason: 'Refund Reason',
     refundReasonPlaceholder: 'Please describe your refund reason',
     stripeLoadFailed: 'Failed to load payment component. Please refresh and try again.',
+    stripeMissingParams: 'Missing order ID or client secret',
+    stripeNotConfigured: 'Stripe is not configured',
     errors: {
       tooManyPending: 'Too many pending orders (max {max}). Please complete or cancel existing orders first.',
       cancelRateLimited: 'Too many cancellations. Please try again later.',
diff --git a/frontend/src/i18n/locales/zh.ts b/frontend/src/i18n/locales/zh.ts
index 8d3b866be3..20a3e33943 100644
--- a/frontend/src/i18n/locales/zh.ts
+++ b/frontend/src/i18n/locales/zh.ts
@@ -5343,6 +5343,8 @@ export default {
     refundReason: '退款原因',
     refundReasonPlaceholder: '请描述您的退款原因',
     stripeLoadFailed: '支付组件加载失败，请刷新页面重试',
+    stripeMissingParams: '缺少订单ID或支付密钥',
+    stripeNotConfigured: 'Stripe 未配置',
     errors: {
       tooManyPending: '待支付订单过多（最多 {max} 个），请先完成或取消现有订单',
       cancelRateLimited: '取消订单过于频繁，请稍后再试',
diff --git a/frontend/src/views/user/PaymentQRCodeView.vue b/frontend/src/views/user/PaymentQRCodeView.vue
index 443707f5dc..50173a1a8d 100644
--- a/frontend/src/views/user/PaymentQRCodeView.vue
+++ b/frontend/src/views/user/PaymentQRCodeView.vue
@@ -182,12 +182,12 @@ watch(qrUrl, () => renderQR())
 
 onMounted(() => {
   orderId.value = Number(route.query.order_id) || 0
-  qrUrl.value = (route.query.qr as string) || ''
-  payUrl.value = (route.query.pay_url as string) || ''
-  paymentType.value = (route.query.payment_type as string) || ''
+  qrUrl.value = String(route.query.qr || '')
+  payUrl.value = String(route.query.pay_url || '')
+  paymentType.value = String(route.query.payment_type || '')
 
   // Calculate countdown from expiresAt
-  const expiresAtStr = route.query.expires_at as string
+  const expiresAtStr = String(route.query.expires_at || '')
   let seconds = 30 * 60 // fallback: 30 minutes
   if (expiresAtStr) {
     const expiresAt = new Date(expiresAtStr)
diff --git a/frontend/src/views/user/PaymentResultView.vue b/frontend/src/views/user/PaymentResultView.vue
index 14ed0e2ee9..d4bb84fe27 100644
--- a/frontend/src/views/user/PaymentResultView.vue
+++ b/frontend/src/views/user/PaymentResultView.vue
@@ -120,14 +120,14 @@ onMounted(async () => {
 
   // Fallback: EasyPay return URL with out_trade_no
   if (!orderId && route.query.out_trade_no) {
-    const outTradeNo = route.query.out_trade_no as string
+    const outTradeNo = String(route.query.out_trade_no || '')
     orderId = parseOutTradeNo(outTradeNo)
     // Store return info for display when order lookup fails
     returnInfo.value = {
       outTradeNo,
-      money: (route.query.money as string) || '',
-      type: (route.query.type as string) || '',
-      tradeStatus: (route.query.trade_status as string) || '',
+      money: String(route.query.money || ''),
+      type: String(route.query.type || ''),
+      tradeStatus: String(route.query.trade_status || ''),
     }
   }
 
diff --git a/frontend/src/views/user/PaymentView.vue b/frontend/src/views/user/PaymentView.vue
index c86b84d1b5..9b199f709d 100644
--- a/frontend/src/views/user/PaymentView.vue
+++ b/frontend/src/views/user/PaymentView.vue
@@ -126,6 +126,7 @@ import AppLayout from '@/components/layout/AppLayout.vue'
 import BaseDialog from '@/components/common/BaseDialog.vue'
 import AmountInput from '@/components/payment/AmountInput.vue'
 import PaymentMethodSelector from '@/components/payment/PaymentMethodSelector.vue'
+import { METHOD_ORDER } from '@/components/payment/providerConfig'
 import SubscriptionPlanCard from '@/components/payment/SubscriptionPlanCard.vue'
 import type { PaymentMethodOption } from '@/components/payment/PaymentMethodSelector.vue'
 
@@ -241,10 +242,12 @@ async function createOrder(orderAmount: number, orderType: string, planId?: numb
       errorMessage.value = t('payment.result.failed')
       appStore.showError(errorMessage.value)
     }
-  } catch (err: any) {
-    if (err.reason === 'TOO_MANY_PENDING') {
-      errorMessage.value = t('payment.errors.tooManyPending', { max: err.metadata?.max || '' })
-    } else if (err.reason === 'CANCEL_RATE_LIMITED') {
+  } catch (err: unknown) {
+    const apiErr = err as Record<string, unknown>
+    if (apiErr.reason === 'TOO_MANY_PENDING') {
+      const metadata = apiErr.metadata as Record<string, unknown> | undefined
+      errorMessage.value = t('payment.errors.tooManyPending', { max: metadata?.max || '' })
+    } else if (apiErr.reason === 'CANCEL_RATE_LIMITED') {
       errorMessage.value = t('payment.errors.cancelRateLimited')
     } else {
       errorMessage.value = extractApiErrorMessage(err, t('payment.result.failed'))
@@ -273,10 +276,10 @@ onMounted(async () => {
       methodLimits.value = limitsRes.data
     } catch (e) { /* limits endpoint may not exist */ }
     if (enabledMethods.value.length) {
-      const METHOD_ORDER = ['alipay', 'wxpay', 'stripe']
+      const order: readonly string[] = METHOD_ORDER
       const sorted = [...enabledMethods.value].sort((a, b) => {
-        const ai = METHOD_ORDER.indexOf(a)
-        const bi = METHOD_ORDER.indexOf(b)
+        const ai = order.indexOf(a)
+        const bi = order.indexOf(b)
         return (ai === -1 ? 999 : ai) - (bi === -1 ? 999 : bi)
       })
       selectedMethod.value = sorted[0]
diff --git a/frontend/src/views/user/StripePaymentView.vue b/frontend/src/views/user/StripePaymentView.vue
index 3e2c818513..a7ec948234 100644
--- a/frontend/src/views/user/StripePaymentView.vue
+++ b/frontend/src/views/user/StripePaymentView.vue
@@ -50,6 +50,7 @@ import { usePaymentStore } from '@/stores/payment'
 import { paymentAPI } from '@/api/payment'
 import { extractApiErrorMessage } from '@/utils/apiError'
 import type { PaymentOrder } from '@/types/payment'
+import type { Stripe, StripeElements } from '@stripe/stripe-js'
 import AppLayout from '@/components/layout/AppLayout.vue'
 import Icon from '@/components/icons/Icon.vue'
 
@@ -66,17 +67,17 @@ const stripeSuccess = ref(false)
 const stripeReady = ref(false)
 const order = ref<PaymentOrder | null>(null)
 
-let stripeInstance: any = null
+let stripeInstance: Stripe | null = null
 let redirectTimer: ReturnType<typeof setTimeout> | null = null
-let elementsInstance: any = null
+let elementsInstance: StripeElements | null = null
 
 onMounted(async () => {
   const orderId = Number(route.query.order_id)
-  const clientSecret = route.query.client_secret as string
+  const clientSecret = String(route.query.client_secret || '')
 
   if (!orderId || !clientSecret) {
     loading.value = false
-    initError.value = 'Missing order ID or client secret'
+    initError.value = t('payment.stripeMissingParams')
     return
   }
 
@@ -86,7 +87,7 @@ onMounted(async () => {
 
     await paymentStore.fetchConfig()
     const publishableKey = paymentStore.config?.stripe_publishable_key
-    if (!publishableKey) { initError.value = 'Stripe is not configured'; return }
+    if (!publishableKey) { initError.value = t('payment.stripeNotConfigured'); return }
 
     const { loadStripe } = await import('@stripe/stripe-js')
     const stripe = await loadStripe(publishableKey)
@@ -107,7 +108,7 @@ onMounted(async () => {
     } as Record<string, unknown>)
     paymentElement.mount('#stripe-payment-element')
     paymentElement.on('ready', () => { stripeReady.value = true })
-  } catch (err: any) {
+  } catch (err: unknown) {
     initError.value = extractApiErrorMessage(err, t('payment.stripeLoadFailed'))
   } finally {
     loading.value = false
@@ -135,10 +136,10 @@ async function handlePay() {
     } else {
       stripeSuccess.value = true
       redirectTimer = setTimeout(() => {
-        router.push({ path: '/payment/result', query: { order_id: route.query.order_id as string, status: 'success' } })
+        router.push({ path: '/payment/result', query: { order_id: String(route.query.order_id || ''), status: 'success' } })
       }, 2000)
     }
-  } catch (err: any) {
+  } catch (err: unknown) {
     stripeError.value = extractApiErrorMessage(err, t('payment.result.failed'))
   } finally {
     stripeSubmitting.value = false