添加渐变色

keyBoard/Assets.xcassets/Tabbar/tabbar_alfe_icon.imageset/Contents.json

@@ -0,0 +1,22 @@
+{
+  "images" : [
+    {
+      "idiom" : "universal",
+      "scale" : "1x"
+    },
+    {
+      "filename" : "tabbar_alfe_icon@2x.png",
+      "idiom" : "universal",
+      "scale" : "2x"
+    },
+    {
+      "filename" : "tabbar_alfe_icon@3x.png",
+      "idiom" : "universal",
+      "scale" : "3x"
+    }
+  ],
+  "info" : {
+    "author" : "xcode",
+    "version" : 1
+  }
+}

keyBoard/Assets.xcassets/Test/person_icon.imageset/Contents.json

@@ -0,0 +1,21 @@
+{
+  "images" : [
+    {
+      "filename" : "person_icon.png",
+      "idiom" : "universal",
+      "scale" : "1x"
+    },
+    {
+      "idiom" : "universal",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "universal",
+      "scale" : "3x"
+    }
+  ],
+  "info" : {
+    "author" : "xcode",
+    "version" : 1
+  }
+}

keyBoard/Class/AiTalk/VC/KBAiMainVC.m

@@ -21,6 +21,10 @@
 @property(nonatomic, strong) UILabel *statusLabel;
 @property(nonatomic, strong) UIButton *commentButton;
 @property(nonatomic, strong) KBAICommentView *commentView;
+@property(nonatomic, strong) UIView *tabbarBackgroundView;
+@property(nonatomic, strong) UIVisualEffectView *blurEffectView;
+@property(nonatomic, strong) CAGradientLayer *gradientLayer;
+@property(nonatomic, strong) UIImageView *personImageView;
 
 // 核心模块
 @property(nonatomic, strong) ConversationOrchestrator *orchestrator;
@@ -34,6 +38,10 @@
 - (void)viewDidLoad {
   [super viewDidLoad];
 
+  // 让视图延伸到屏幕边缘（包括状态栏和导航栏下方）
+  self.edgesForExtendedLayout = UIRectEdgeAll;
+  self.extendedLayoutIncludesOpaqueBars = YES;
+
   [self setupUI];
   [self setupOrchestrator];
 }
@@ -45,6 +53,54 @@
   [self.orchestrator stop];
 }
 
+- (void)viewDidLayoutSubviews {
+  [super viewDidLayoutSubviews];
+
+  // 设置黑色渐变层（从底部到顶部，黑色到透明）
+  if (!self.gradientLayer) {
+    self.gradientLayer = [CAGradientLayer layer];
+    self.gradientLayer.startPoint = CGPointMake(0.53, 1); // 底部
+    self.gradientLayer.endPoint = CGPointMake(0.54, 0);   // 顶部
+    // 渐变颜色：从黑色 24% 不透明度到透明
+    self.gradientLayer.colors = @[
+      (__bridge id)[UIColor colorWithRed:0 / 255.0
+                                   green:0 / 255.0
+                                    blue:0 / 255.0
+                                   alpha:0.24]
+          .CGColor,
+      (__bridge id)[UIColor colorWithRed:3 / 255.0
+                                   green:3 / 255.0
+                                    blue:3 / 255.0
+                                   alpha:0]
+          .CGColor
+    ];
+    self.gradientLayer.locations = @[ @(0.7), @(1.0) ];
+    [self.tabbarBackgroundView.layer addSublayer:self.gradientLayer];
+  }
+
+  // 更新黑色渐变层的 frame
+  self.gradientLayer.frame = self.tabbarBackgroundView.bounds;
+
+  // 为 blurEffectView 添加透明度渐变
+  // mask（从底部到中间不透明，从中间到顶部透明）
+  if (!self.blurEffectView.layer.mask) {
+    CAGradientLayer *maskLayer = [CAGradientLayer layer];
+    maskLayer.startPoint = CGPointMake(0.5, 1); // 底部
+    maskLayer.endPoint = CGPointMake(0.5, 0);   // 顶部
+    // 底部到中间保持不透明，从中间到顶部过渡透明
+    maskLayer.colors = @[
+      (__bridge id)[UIColor whiteColor].CGColor, // 底部：完全不透明
+      (__bridge id)[UIColor whiteColor].CGColor, // 中间：完全不透明
+      (__bridge id)[UIColor clearColor].CGColor  // 顶部：完全透明
+    ];
+    maskLayer.locations = @[ @(0.0), @(0.5), @(1.0) ];
+    self.blurEffectView.layer.mask = maskLayer;
+  }
+
+  // 更新 mask 的 frame
+  self.blurEffectView.layer.mask.frame = self.blurEffectView.bounds;
+}
+
 #pragma mark - UI Setup
 
 - (void)setupUI {
@@ -54,6 +110,29 @@
   // 安全区域
   UILayoutGuide *safeArea = self.view.safeAreaLayoutGuide;
 
+  // PersonImageView（背景图，最底层）
+  self.personImageView =
+      [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"person_icon"]];
+  [self.view addSubview:self.personImageView];
+  [self.personImageView mas_makeConstraints:^(MASConstraintMaker *make) {
+    make.left.right.top.bottom.equalTo(self.view);
+  }];
+
+  // TabBar 毛玻璃模糊背景（在 personImageView 之上）
+  self.tabbarBackgroundView = [[UIView alloc] init];
+  self.tabbarBackgroundView.translatesAutoresizingMaskIntoConstraints = NO;
+  self.tabbarBackgroundView.clipsToBounds = YES;
+  [self.view addSubview:self.tabbarBackgroundView];
+
+  // 模糊效果
+  UIBlurEffect *blurEffect =
+      [UIBlurEffect effectWithStyle:UIBlurEffectStyleLight];
+  self.blurEffectView = [[UIVisualEffectView alloc] initWithEffect:blurEffect];
+  self.blurEffectView.translatesAutoresizingMaskIntoConstraints = NO;
+  [self.tabbarBackgroundView addSubview:self.blurEffectView];
+
+  // 渐变层将在 viewDidLayoutSubviews 中设置
+
   // 状态标签
   self.statusLabel = [[UILabel alloc] init];
   self.statusLabel.text = @"按住按钮开始对话";
@@ -64,10 +143,10 @@
   [self.view addSubview:self.statusLabel];
 
   // 聊天视图
-  self.chatView = [[KBAiChatView alloc] init];
-  self.chatView.backgroundColor = [UIColor systemBackgroundColor];
-  self.chatView.translatesAutoresizingMaskIntoConstraints = NO;
-  [self.view addSubview:self.chatView];
+  //  self.chatView = [[KBAiChatView alloc] init];
+  //  self.chatView.backgroundColor = [UIColor systemBackgroundColor];
+  //  self.chatView.translatesAutoresizingMaskIntoConstraints = NO;
+  //  [self.view addSubview:self.chatView];
 
   // 录音按钮
   self.recordButton = [[KBAiRecordButton alloc] init];
@@ -92,51 +171,34 @@
                forControlEvents:UIControlEventTouchUpInside];
   [self.view addSubview:self.commentButton];
 
-  // 布局约束
-  [NSLayoutConstraint activateConstraints:@[
-    // 状态标签
-    [self.statusLabel.topAnchor constraintEqualToAnchor:safeArea.topAnchor
-                                               constant:8],
-    [self.statusLabel.leadingAnchor
-        constraintEqualToAnchor:safeArea.leadingAnchor
-                       constant:16],
-    [self.statusLabel.trailingAnchor
-        constraintEqualToAnchor:safeArea.trailingAnchor
-                       constant:-16],
+  // 布局约束 - 使用 Masonry
+  [self.tabbarBackgroundView mas_makeConstraints:^(MASConstraintMaker *make) {
+    make.left.right.bottom.equalTo(self.view);
+    make.height.mas_equalTo(KBFit(238));
+  }];
 
-    // 聊天视图
-    [self.chatView.topAnchor
-        constraintEqualToAnchor:self.statusLabel.bottomAnchor
-                       constant:8],
-    [self.chatView.leadingAnchor
-        constraintEqualToAnchor:safeArea.leadingAnchor],
-    [self.chatView.trailingAnchor
-        constraintEqualToAnchor:safeArea.trailingAnchor],
-    [self.chatView.bottomAnchor
-        constraintEqualToAnchor:self.recordButton.topAnchor
-                       constant:-16],
+  [self.blurEffectView mas_makeConstraints:^(MASConstraintMaker *make) {
+    make.edges.equalTo(self.tabbarBackgroundView);
+  }];
 
-    // 录音按钮
-    [self.recordButton.leadingAnchor
-        constraintEqualToAnchor:safeArea.leadingAnchor
-                       constant:20],
-    [self.recordButton.trailingAnchor
-        constraintEqualToAnchor:safeArea.trailingAnchor
-                       constant:-20],
-    [self.recordButton.bottomAnchor
-        constraintEqualToAnchor:safeArea.bottomAnchor
-                       constant:-16],
-    [self.recordButton.heightAnchor constraintEqualToConstant:50],
+  [self.statusLabel mas_makeConstraints:^(MASConstraintMaker *make) {
+    make.top.equalTo(self.view.mas_safeAreaLayoutGuideTop).offset(8);
+    make.left.equalTo(self.view).offset(16);
+    make.right.equalTo(self.view).offset(-16);
+  }];
 
-    // 评论按钮（右侧居中）
-    [self.commentButton.trailingAnchor
-        constraintEqualToAnchor:safeArea.trailingAnchor
-                       constant:-16],
-    [self.commentButton.centerYAnchor
-        constraintEqualToAnchor:self.chatView.centerYAnchor],
-    [self.commentButton.widthAnchor constraintEqualToConstant:50],
-    [self.commentButton.heightAnchor constraintEqualToConstant:50],
-  ]];
+  [self.recordButton mas_makeConstraints:^(MASConstraintMaker *make) {
+    make.left.equalTo(self.view.mas_safeAreaLayoutGuideLeft).offset(20);
+    make.right.equalTo(self.view.mas_safeAreaLayoutGuideRight).offset(-20);
+    make.bottom.equalTo(self.view.mas_safeAreaLayoutGuideBottom).offset(-16);
+    make.height.mas_equalTo(50);
+  }];
+
+  [self.commentButton mas_makeConstraints:^(MASConstraintMaker *make) {
+    make.right.equalTo(self.view.mas_safeAreaLayoutGuideRight).offset(-16);
+    make.centerY.equalTo(self.view);
+    make.width.height.mas_equalTo(50);
+  }];
 }
 
 #pragma mark - Orchestrator Setup
@@ -240,25 +302,25 @@
 
 #pragma mark - 事件
 - (void)showComment {
-    CGFloat customViewHeight = KB_SCREEN_HEIGHT * (0.8);
-    KBAICommentView *customView = [[KBAICommentView alloc]
-                                   initWithFrame:CGRectMake(0, 0, KB_SCREEN_WIDTH, customViewHeight)];
-    LSTPopView *popView =
-    [LSTPopView initWithCustomView:customView
-                        parentView:nil
-                          popStyle:LSTPopStyleSmoothFromBottom
-                      dismissStyle:LSTDismissStyleSmoothToBottom];
-    self.popView = popView;
-    popView.priority = 1000;
-    popView.isAvoidKeyboard = false;
-    popView.hemStyle = LSTHemStyleBottom;
-    popView.dragStyle = LSTDragStyleY_Positive;
-    popView.dragDistance = customViewHeight * 0.5;
-    popView.sweepStyle = LSTSweepStyleY_Positive;
-    popView.swipeVelocity = 1600;
-    popView.sweepDismissStyle = LSTSweepDismissStyleSmooth;
+  CGFloat customViewHeight = KB_SCREEN_HEIGHT * (0.8);
+  KBAICommentView *customView = [[KBAICommentView alloc]
+      initWithFrame:CGRectMake(0, 0, KB_SCREEN_WIDTH, customViewHeight)];
+  LSTPopView *popView =
+      [LSTPopView initWithCustomView:customView
+                          parentView:nil
+                            popStyle:LSTPopStyleSmoothFromBottom
+                        dismissStyle:LSTDismissStyleSmoothToBottom];
+  self.popView = popView;
+  popView.priority = 1000;
+  popView.isAvoidKeyboard = false;
+  popView.hemStyle = LSTHemStyleBottom;
+  popView.dragStyle = LSTDragStyleY_Positive;
+  popView.dragDistance = customViewHeight * 0.5;
+  popView.sweepStyle = LSTSweepStyleY_Positive;
+  popView.swipeVelocity = 1600;
+  popView.sweepDismissStyle = LSTSweepDismissStyleSmooth;
 
-    [popView pop];
+  [popView pop];
 }
 
 - (void)showCommentDirectly {
@@ -268,12 +330,14 @@
   }
 
   CGFloat customViewHeight = KB_SCREEN_HEIGHT * (0.8);
-  KBAICommentView *customView = [[KBAICommentView alloc] initWithFrame:CGRectZero];
+  KBAICommentView *customView =
+      [[KBAICommentView alloc] initWithFrame:CGRectZero];
   customView.translatesAutoresizingMaskIntoConstraints = NO;
   [self.view addSubview:customView];
   [NSLayoutConstraint activateConstraints:@[
     [customView.leadingAnchor constraintEqualToAnchor:self.view.leadingAnchor],
-    [customView.trailingAnchor constraintEqualToAnchor:self.view.trailingAnchor],
+    [customView.trailingAnchor
+        constraintEqualToAnchor:self.view.trailingAnchor],
     [customView.bottomAnchor constraintEqualToAnchor:self.view.bottomAnchor],
     [customView.heightAnchor constraintEqualToConstant:customViewHeight],
   ]];

keyBoard/Class/Base/VC/BaseTabBarController.m

@@ -7,132 +7,215 @@
 
 #import "BaseTabBarController.h"
 #import "HomeMainVC.h"
-#import "MyVC.h"
-#import "KBShopVC.h"
 #import "KBAiMainVC.h"
+#import "KBShopVC.h"
+#import "MyVC.h"
 
-//#import "KBCommunityVC.h"
+// #import "KBCommunityVC.h"
 
 #import "BaseNavigationController.h"
 #import "KBAuthManager.h"
 @interface BaseTabBarController ()
 
+/// 原始的 TabBar appearance（用于恢复）
+@property(nonatomic, strong)
+    UITabBarAppearance *originalAppearance API_AVAILABLE(ios(13.0));
+@property(nonatomic, strong)
+    UITabBarAppearance *transparentAppearance API_AVAILABLE(ios(13.0));
+
 @end
 
 @implementation BaseTabBarController
 
 - (void)viewDidLoad {
-    [super viewDidLoad];
+  [super viewDidLoad];
 
-    self.delegate = self;
+  self.delegate = self;
 
-    [self setupTabbarAppearance];
+  [self setupTabbarAppearance];
 
-    // 组装 4 个 Tab：首页 / 商城 / 社区 / 我的
-    // 图标位于 Assets.xcassets/Tabbar 下：tab_home/tab_home_selected 等
+  // 组装 4 个 Tab：首页 / 商城 / 社区 / 我的
+  // 图标位于 Assets.xcassets/Tabbar 下：tab_home/tab_home_selected 等
 
-    // 首页
-    HomeMainVC *home = [[HomeMainVC alloc] init];
-    BaseNavigationController *navHome = [[BaseNavigationController alloc] initWithRootViewController:home];
-    navHome.tabBarItem = [self tabItemWithTitle:KBLocalized(@"Home")
+  // 首页
+  HomeMainVC *home = [[HomeMainVC alloc] init];
+  BaseNavigationController *navHome =
+      [[BaseNavigationController alloc] initWithRootViewController:home];
+  navHome.tabBarItem = [self tabItemWithTitle:KBLocalized(@"Home")
                                         image:@"tab_home"
                                   selectedImg:@"tab_home_selected"];
 
-    // 商城
-    KBShopVC *shop = [[KBShopVC alloc] init];
-    BaseNavigationController *navShop = [[BaseNavigationController alloc] initWithRootViewController:shop];
-    navShop.tabBarItem = [self tabItemWithTitle:KBLocalized(@"Shop")
+  // 商城
+  KBShopVC *shop = [[KBShopVC alloc] init];
+  BaseNavigationController *navShop =
+      [[BaseNavigationController alloc] initWithRootViewController:shop];
+  navShop.tabBarItem = [self tabItemWithTitle:KBLocalized(@"Shop")
                                         image:@"tab_shop"
                                   selectedImg:@"tab_shop_selected"];
 
-    // AI
-    KBAiMainVC *aiMainVC = [[KBAiMainVC alloc] init];
-//    community.title = KBLocalized(@"Circle");
-    BaseNavigationController *navCommunity = [[BaseNavigationController alloc] initWithRootViewController:aiMainVC];
-    navCommunity.tabBarItem = [self tabItemWithTitle:KBLocalized(@"Circle")
+  // AI
+  KBAiMainVC *aiMainVC = [[KBAiMainVC alloc] init];
+  //    community.title = KBLocalized(@"Circle");
+  BaseNavigationController *navCommunity =
+      [[BaseNavigationController alloc] initWithRootViewController:aiMainVC];
+  navCommunity.tabBarItem = [self tabItemWithTitle:KBLocalized(@"Circle")
                                              image:@"tab_shequ"
                                        selectedImg:@"tab_shequ_selected"];
 
-    // 我的
-    MyVC *my = [[MyVC alloc] init];
-    BaseNavigationController *navMy = [[BaseNavigationController alloc] initWithRootViewController:my];
-    navMy.tabBarItem = [self tabItemWithTitle:KBLocalized(@"Mine")
-                                       image:@"tab_my"
-                                 selectedImg:@"tab_my_selected"];
+  // 我的
+  MyVC *my = [[MyVC alloc] init];
+  BaseNavigationController *navMy =
+      [[BaseNavigationController alloc] initWithRootViewController:my];
+  navMy.tabBarItem = [self tabItemWithTitle:KBLocalized(@"Mine")
+                                      image:@"tab_my"
+                                selectedImg:@"tab_my_selected"];
 
-    self.viewControllers = @[aiMainVC,navHome, navShop, navMy];
+  self.viewControllers = @[ navHome, navShop, aiMainVC, navMy ];
 
-    // 测试储存Token
-//    [[KBAuthManager shared] saveAccessToken:@"TEST" refreshToken:nil expiryDate:[NSDate dateWithTimeIntervalSinceNow:3600] userIdentifier:nil];
-//    [[KBAuthManager shared] signOut];
+  // 测试储存Token
+  //    [[KBAuthManager shared] saveAccessToken:@"TEST" refreshToken:nil
+  //    expiryDate:[NSDate dateWithTimeIntervalSinceNow:3600]
+  //    userIdentifier:nil];
+  //    [[KBAuthManager shared] signOut];
 }
 
-- (void)setupTabbarAppearance{
-    // 让 TabBar 不透明，子控制器 view 不再延伸到 TabBar 下
-      self.tabBar.translucent = NO;
-      if (@available(iOS 15.0, *)) {
-          UITabBarAppearance *a = [UITabBarAppearance new];
-          [a configureWithOpaqueBackground];
-          a.backgroundColor = [UIColor whiteColor];
-          // 设置选中标题为黑色（iOS 15+ 需通过 appearance）
-          NSDictionary *selAttr = @{ NSForegroundColorAttributeName : [UIColor blackColor] };
-          a.stackedLayoutAppearance.selected.titleTextAttributes = selAttr;
-          a.inlineLayoutAppearance.selected.titleTextAttributes = selAttr;
-          a.compactInlineLayoutAppearance.selected.titleTextAttributes = selAttr;
-          self.tabBar.standardAppearance = a;
-          self.tabBar.scrollEdgeAppearance = a;
-      } else if (@available(iOS 13.0, *)) {
-          UITabBarAppearance *a = [UITabBarAppearance new];
-          [a configureWithOpaqueBackground];
-          a.backgroundColor = [UIColor whiteColor];
-          NSDictionary *selAttr = @{ NSForegroundColorAttributeName : [UIColor blackColor] };
-          a.stackedLayoutAppearance.selected.titleTextAttributes = selAttr;
-          a.inlineLayoutAppearance.selected.titleTextAttributes = selAttr;
-          a.compactInlineLayoutAppearance.selected.titleTextAttributes = selAttr;
-          self.tabBar.standardAppearance = a;
-          self.tabBar.tintColor = [UIColor blackColor];
-      } else {
-          // 老系统用 tintColor/appearance 做回退
-          self.tabBar.tintColor = [UIColor blackColor];
-          [[UITabBarItem appearance] setTitleTextAttributes:@{NSForegroundColorAttributeName:[UIColor blackColor]}
-                                                   forState:UIControlStateSelected];
-      }
+- (void)setupTabbarAppearance {
+  // 让 TabBar 不透明，子控制器 view 不再延伸到 TabBar 下
+  self.tabBar.translucent = NO;
+  if (@available(iOS 15.0, *)) {
+    UITabBarAppearance *a = [UITabBarAppearance new];
+    [a configureWithOpaqueBackground];
+    a.backgroundColor = [UIColor whiteColor];
+    // 设置选中标题为黑色（iOS 15+ 需通过 appearance）
+    NSDictionary *selAttr =
+        @{NSForegroundColorAttributeName : [UIColor blackColor]};
+    a.stackedLayoutAppearance.selected.titleTextAttributes = selAttr;
+    a.inlineLayoutAppearance.selected.titleTextAttributes = selAttr;
+    a.compactInlineLayoutAppearance.selected.titleTextAttributes = selAttr;
+    self.tabBar.standardAppearance = a;
+    self.tabBar.scrollEdgeAppearance = a;
+
+    // 保存原始 appearance
+    self.originalAppearance = a;
+
+    // 创建透明 appearance
+    UITabBarAppearance *transparentA = [UITabBarAppearance new];
+    [transparentA configureWithTransparentBackground];
+    transparentA.backgroundColor = [UIColor clearColor];
+    transparentA.stackedLayoutAppearance.selected.titleTextAttributes = selAttr;
+    transparentA.inlineLayoutAppearance.selected.titleTextAttributes = selAttr;
+    transparentA.compactInlineLayoutAppearance.selected.titleTextAttributes =
+        selAttr;
+    self.transparentAppearance = transparentA;
+  } else if (@available(iOS 13.0, *)) {
+    UITabBarAppearance *a = [UITabBarAppearance new];
+    [a configureWithOpaqueBackground];
+    a.backgroundColor = [UIColor whiteColor];
+    NSDictionary *selAttr =
+        @{NSForegroundColorAttributeName : [UIColor blackColor]};
+    a.stackedLayoutAppearance.selected.titleTextAttributes = selAttr;
+    a.inlineLayoutAppearance.selected.titleTextAttributes = selAttr;
+    a.compactInlineLayoutAppearance.selected.titleTextAttributes = selAttr;
+    self.tabBar.standardAppearance = a;
+    self.tabBar.tintColor = [UIColor blackColor];
+
+    // 保存原始 appearance
+    self.originalAppearance = a;
+
+    // 创建透明 appearance
+    UITabBarAppearance *transparentA = [UITabBarAppearance new];
+    [transparentA configureWithTransparentBackground];
+    transparentA.backgroundColor = [UIColor clearColor];
+    transparentA.stackedLayoutAppearance.selected.titleTextAttributes = selAttr;
+    transparentA.inlineLayoutAppearance.selected.titleTextAttributes = selAttr;
+    transparentA.compactInlineLayoutAppearance.selected.titleTextAttributes =
+        selAttr;
+    self.transparentAppearance = transparentA;
+  } else {
+    // 老系统用 tintColor/appearance 做回退
+    self.tabBar.tintColor = [UIColor blackColor];
+    [[UITabBarItem appearance] setTitleTextAttributes:@{
+      NSForegroundColorAttributeName : [UIColor blackColor]
+    }
+                                             forState:UIControlStateSelected];
+  }
 }
 
 // 统一构造 TabBarItem，原图渲染，避免被系统 Tint 着色
-- (UITabBarItem *)tabItemWithTitle:(NSString *)title image:(NSString *)imageName selectedImg:(NSString *)selectedName {
-    UIImage *img = [[UIImage imageNamed:imageName] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
-    UIImage *sel = [[UIImage imageNamed:selectedName] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
-    UITabBarItem *item = [[UITabBarItem alloc] initWithTitle:title image:img selectedImage:sel];
-    return item;
+- (UITabBarItem *)tabItemWithTitle:(NSString *)title
+                             image:(NSString *)imageName
+                       selectedImg:(NSString *)selectedName {
+  UIImage *img = [[UIImage imageNamed:imageName]
+      imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
+  UIImage *sel = [[UIImage imageNamed:selectedName]
+      imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
+  UITabBarItem *item = [[UITabBarItem alloc] initWithTitle:title
+                                                     image:img
+                                             selectedImage:sel];
+  return item;
 }
 
 #pragma mark - UITabBarControllerDelegate
 
-- (BOOL)tabBarController:(UITabBarController *)tabBarController shouldSelectViewController:(UIViewController *)viewController {
-    // 已经是当前选中的 tab，直接允许（避免重复拦截）
-    if (tabBarController.selectedViewController == viewController) {
-        return YES;
-    }
-
-    NSUInteger index = [tabBarController.viewControllers indexOfObject:viewController];
-    if (index == NSNotFound) {
-        return YES;
-    }
-
-    // “我的” tab 默认为第 4 个（索引 3），未登录时先跳转登录页
-    if ((index == 1 || index == 2) && ![KBUserSessionManager shared].isLoggedIn) {
-        [[KBUserSessionManager shared] goLoginVC];
-        return NO;
-    }
-
+- (BOOL)tabBarController:(UITabBarController *)tabBarController
+    shouldSelectViewController:(UIViewController *)viewController {
+  // 已经是当前选中的 tab，直接允许（避免重复拦截）
+  if (tabBarController.selectedViewController == viewController) {
     return YES;
+  }
+
+  NSUInteger index =
+      [tabBarController.viewControllers indexOfObject:viewController];
+  if (index == NSNotFound) {
+    return YES;
+  }
+
+  // “我的” tab 默认为第 4 个（索引 3），未登录时先跳转登录页
+  if ((index == 1 || index == 2) && ![KBUserSessionManager shared].isLoggedIn) {
+    [[KBUserSessionManager shared] goLoginVC];
+    return NO;
+  }
+
+  return YES;
+}
+
+- (void)tabBarController:(UITabBarController *)tabBarController
+    didSelectViewController:(UIViewController *)viewController {
+  NSUInteger index =
+      [tabBarController.viewControllers indexOfObject:viewController];
+
+  // 第三个 tab（索引2）是 KBAiMainVC，背景透明
+  if (index == 2) {
+    if (@available(iOS 13.0, *)) {
+      self.tabBar.standardAppearance = self.transparentAppearance;
+      if (@available(iOS 15.0, *)) {
+        self.tabBar.scrollEdgeAppearance = self.transparentAppearance;
+      }
+    } else {
+      // iOS 13 以下，直接设置背景色
+      self.tabBar.barTintColor = [UIColor clearColor];
+      self.tabBar.backgroundColor = [UIColor clearColor];
+    }
+  } else {
+    // 其他 tab，恢复原始背景
+    if (@available(iOS 13.0, *)) {
+      self.tabBar.standardAppearance = self.originalAppearance;
+      if (@available(iOS 15.0, *)) {
+        self.tabBar.scrollEdgeAppearance = self.originalAppearance;
+      }
+    } else {
+      // iOS 13 以下，恢复白色背景
+      self.tabBar.barTintColor = [UIColor whiteColor];
+      self.tabBar.backgroundColor = [UIColor whiteColor];
+    }
+  }
 }
 
 /*
 #pragma mark - Navigation
 
-// In a storyboard-based application, you will often want to do a little preparation before navigation
+// In a storyboard-based application, you will often want to do a little
+preparation before navigation
 - (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
     // Get the new view controller using [segue destinationViewController].
     // Pass the selected object to the new view controller.