style: 完成京东风格整体改造

1.  启用京东红主题，替换全局主色调为#e4393c
2.  调整侧边栏宽度为200px，优化导航样式
3.  重构顶部导航、侧边菜单、表格、卡片等全局组件样式
4.  新增JdStatusTabs和JdFilterBar通用组件
5.  统一业务页面配色风格为红白灰配色方案
6.  修复物料列表空数据展示问题，优化表格样式
7.  新增京东风格改造文档说明

ruoyi-ui/src/views/bid/material/index.vue

@@ -42,8 +42,8 @@
           :data="materialList"
           @selection-change="handleSelectionChange"
           border stripe style="width:100%"
-          :header-cell-style="{ background: '#f5f7fa', color: '#303133', fontWeight: 700, fontSize: '13px' }"
-          :cell-style="{ fontSize: '12px', color: '#606266' }"
+          :header-cell-style="{ background: '#f5f5f5', color: '#666', fontWeight: 500, fontSize: '12px' }"
+          :cell-style="{ fontSize: '12px', color: '#333' }"
           size="small">
           <el-table-column type="selection" width="44" align="center" />
           <el-table-column label="物料编码" prop="materialCode" width="120" header-align="center" align="center" />
@@ -66,6 +66,7 @@
             </template>
           </el-table-column>
         </el-table>
+        <el-empty v-if="!loading && total === 0" description="暂无物料数据（请检查后端接口是否正常）" />
         <pagination v-show="total>0" :total="total" :page.sync="queryParams.pageNum" :limit.sync="queryParams.pageSize" @pagination="getList" />
       </el-tab-pane>
 
@@ -253,8 +254,12 @@ export default {
     getList() {
       this.loading = true;
       listMaterial(this.queryParams).then(res => {
-        this.materialList = res.rows;
-        this.total = res.total;
+        this.materialList = res.rows || [];
+        this.total = res.total || 0;
+        this.loading = false;
+      }).catch(() => {
+        this.materialList = [];
+        this.total = 0;
         this.loading = false;
       });
     },