feat(pc): 详情页增加吸顶返回列表按钮，首页按筛选签名恢复滚动位置

frontend/src/features/mohong/views/MohongDetailView.vue

@@ -2,6 +2,8 @@
 import { computed, onMounted, ref } from 'vue'
 import { useRoute, useRouter } from 'vue-router'
 import { ElMessage } from 'element-plus'
+import { ArrowLeft } from '@element-plus/icons-vue'
+import { goBackOrHome } from '@/shared/utils/routerBack'
 import {
   createMohongOrder,
   fetchMohongProduct,
@@ -69,6 +71,10 @@ const activePayWayLabel = computed(() => {
 
 onMounted(loadProduct)
 
+function goBack() {
+  goBackOrHome(router)
+}
+
 async function loadProduct() {
   loading.value = true
   try {
@@ -162,6 +168,12 @@ async function handleBuy() {
 
 <template>
   <section v-loading="loading" class="mohong-detail-page">
+    <div class="detail-back-bar">
+      <button class="detail-back-btn" type="button" @click="goBack">
+        <el-icon><ArrowLeft /></el-icon>
+        <span>返回列表</span>
+      </button>
+    </div>
     <template v-if="product">
       <div class="detail-layout">
         <div class="gallery-panel">
@@ -307,6 +319,44 @@ async function handleBuy() {
   width: 100%;
 }
 
+.detail-back-bar {
+  /* 吸顶固定：始终显示在顶部导航栏（64px）下方，滚动时不跟随页面移走 */
+  position: sticky;
+  top: 78px;
+  z-index: 20;
+  display: flex;
+  align-items: center;
+  margin-bottom: 14px;
+}
+
+.detail-back-btn {
+  display: inline-flex;
+  align-items: center;
+  gap: 6px;
+  height: 36px;
+  padding: 0 14px;
+  border: 1px solid #eef1f5;
+  border-radius: 10px;
+  background: #ffffff;
+  color: #475569;
+  font-size: 13px;
+  font-weight: 700;
+  cursor: pointer;
+  box-shadow: 0 2px 8px rgba(23, 35, 61, 0.08);
+  transition:
+    border-color 0.2s ease,
+    color 0.2s ease,
+    background 0.2s ease,
+    box-shadow 0.2s ease;
+}
+
+.detail-back-btn:hover {
+  border-color: #ff6a00;
+  background: #fff7ed;
+  color: #ff6a00;
+  box-shadow: 0 4px 12px rgba(255, 106, 0, 0.12);
+}
+
 .detail-layout {
   display: grid;
   /* 左图固定合理宽度，右侧信息铺满剩余空间，避免整页右侧大片空白 */