style: 优化为黑金/白金配色方案

- 暗色主题: 黑金传奇 (深黑 + 真金)
- 亮色主题: 白金殿堂 (纯白 + 金色)
- 统一品牌色: 金色强调
- 提升专业金融感

flutter_monisuo/lib/ui/pages/main/main_page.dart

@@ -129,24 +129,19 @@ class _BottomNavBar extends StatelessWidget {
           ),
         ],
       ),
-      child: ClipRRect(
-        borderRadius: BorderRadius.vertical(top: Radius.circular(AppRadius.xxl + AppSpacing.sm)),
-        child: BackdropFilter(
-          filter: ImageFilter.blur(sigmaX: AppSpacing.md, sigmaY: AppSpacing.md),
-          child: SafeArea(
-            child: Padding(
-              padding: EdgeInsets.fromLTRB(AppSpacing.md, AppSpacing.sm, AppSpacing.md, AppSpacing.lg),
-              child: Row(
-                mainAxisAlignment: MainAxisAlignment.spaceAround,
-                children: items.asMap().entries.map((entry) {
-                  return _NavItemWidget(
-                    item: entry.value,
-                    isSelected: entry.key == currentIndex,
-                    onTap: () => onTap(entry.key),
-                  );
-                }).toList(),
-              ),
-            ),
+      // 【优化】移除毛玻璃效果，保持简洁的半透明背景
+      child: SafeArea(
+        child: Padding(
+          padding: EdgeInsets.fromLTRB(AppSpacing.md, AppSpacing.sm, AppSpacing.md, AppSpacing.lg),
+          child: Row(
+            mainAxisAlignment: MainAxisAlignment.spaceAround,
+            children: items.asMap().entries.map((entry) {
+              return _NavItemWidget(
+                item: entry.value,
+                isSelected: entry.key == currentIndex,
+                onTap: () => onTap(entry.key),
+              );
+            }).toList(),
           ),
         ),
       ),