fix(MarketDataView): loading 背景色改为深色与整体一致

- 移除白色 ThemedCard 包装
- 使用 gray.900 背景 + 金色边框

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/views/Company/components/MarketDataView/index.tsx

@@ -5,10 +5,6 @@ import React, { useState, useEffect, ReactNode, useMemo, useCallback } from 'rea
 import {
   Box,
   Container,
-  CardBody,
-  Center,
-  VStack,
-  Text,
   useDisclosure,
 } from '@chakra-ui/react';
 import {
@@ -161,11 +157,14 @@ const MarketDataView: React.FC<MarketDataViewProps> = ({ stockCode: propStockCod
 
           {/* 主要内容区域 - Tab */}
           {loading ? (
-            <ThemedCard theme={theme}>
-              <CardBody>
-                <LoadingState message="数据加载中..." height="400px" />
-              </CardBody>
-            </ThemedCard>
+            <Box
+              bg="gray.900"
+              border="1px solid"
+              borderColor="rgba(212, 175, 55, 0.3)"
+              borderRadius="xl"
+            >
+              <LoadingState message="数据加载中..." height="400px" />
+            </Box>
           ) : (
             <SubTabContainer
               tabs={tabConfigs}