factor:布局颜色重构

lib/layout/app_navbar.dart

@@ -0,0 +1,43 @@
+import 'package:flisp_app/provider/app_provider.dart';
+import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
+
+class AppNavbar extends StatelessWidget {
+  AppNavbar({super.key});
+
+  final List<BottomNavigationBarItem> navItems = [
+    BottomNavigationBarItem(icon: Icon(Icons.flash_on), label: '闪灵'),
+    BottomNavigationBarItem(icon: Icon(Icons.checklist), label: '待办'),
+    BottomNavigationBarItem(icon: Icon(Icons.calendar_month), label: '日程'),
+    BottomNavigationBarItem(icon: Icon(Icons.insert_chart), label: '统计'),
+  ];
+
+  @override
+  Widget build(BuildContext context) {
+    final appProvider = context.watch<AppProvider>();
+    final colors = Theme.of(context).colorScheme;
+
+    return Container(
+      decoration: BoxDecoration(
+        boxShadow: [
+          BoxShadow(
+            color: colors.shadow.withAlpha(20),
+            blurRadius: 8,
+            offset: const Offset(0, -2),
+          ),
+        ],
+      ),
+      child: BottomNavigationBar(
+        currentIndex: appProvider.currentTab,
+        onTap: (index) => appProvider.changeTab(index),
+        type: BottomNavigationBarType.fixed,
+        backgroundColor: colors.surface,
+        selectedItemColor: colors.primary,
+        unselectedItemColor: colors.onSurface.withAlpha(120),
+        showSelectedLabels: true,
+        showUnselectedLabels: true,
+        items: navItems,
+      ),
+    );
+  }
+}