diff --git a/CustomKeyboard/KeyboardViewController.m b/CustomKeyboard/KeyboardViewController.m
index 73d4c56..9ef1e72 100644
--- a/CustomKeyboard/KeyboardViewController.m
+++ b/CustomKeyboard/KeyboardViewController.m
@@ -30,6 +30,9 @@
 #import "UIImage+KBColor.h"
 #import <AVFoundation/AVFoundation.h>
 #import <SDWebImage/SDWebImage.h>
+#if DEBUG
+#import <mach/mach.h>
+#endif
 
 // #import "KBLog.h"
 
@@ -94,6 +97,8 @@ static void KBSkinInstallNotificationCallback(CFNotificationCenterRef center,
 @property(nonatomic, assign) CGFloat kb_lastKeyboardHeight;
 @property(nonatomic, strong) UIImage *kb_cachedGradientImage;
 @property(nonatomic, assign) CGSize kb_cachedGradientSize;
+@property(nonatomic, strong, nullable) CAGradientLayer *kb_defaultGradientLayer;
+@property(nonatomic, copy, nullable) NSString *kb_lastAppliedThemeKey;
 @property(nonatomic, strong) NSMutableArray<KBChatMessage *> *chatMessages;
 @property(nonatomic, strong) AVAudioPlayer *chatAudioPlayer;
 @property(nonatomic, assign) BOOL chatPanelVisible;
@@ -101,14 +106,45 @@ static void KBSkinInstallNotificationCallback(CFNotificationCenterRef center,
 @property(nonatomic, strong, nullable) id kb_skinObserverToken;
 @end
 
+#if DEBUG
+static NSInteger sKBKeyboardVCAliveCount = 0;
+
+static uint64_t KBPhysFootprintBytes(void) {
+  task_vm_info_data_t vmInfo;
+  mach_msg_type_number_t count = TASK_VM_INFO_COUNT;
+  kern_return_t kr = task_info(mach_task_self(), TASK_VM_INFO,
+                               (task_info_t)&vmInfo, &count);
+  if (kr != KERN_SUCCESS) {
+    return 0;
+  }
+  return (uint64_t)vmInfo.phys_footprint;
+}
+
+static NSString *KBFormatMB(uint64_t bytes) {
+  double mb = (double)bytes / 1024.0 / 1024.0;
+  return [NSString stringWithFormat:@"%.1fMB", mb];
+}
+#endif
+
 @implementation KeyboardViewController
 
 {
   BOOL _kb_didTriggerLoginDeepLinkOnce;
+#if DEBUG
+  BOOL _kb_debugDidCountAlive;
+#endif
 }
 
 - (void)viewDidLoad {
   [super viewDidLoad];
+#if DEBUG
+  if (!_kb_debugDidCountAlive) {
+    _kb_debugDidCountAlive = YES;
+    sKBKeyboardVCAliveCount += 1;
+  }
+  NSLog(@"[Keyboard] KeyboardViewController viewDidLoad alive=%ld self=%p mem=%@",
+        (long)sKBKeyboardVCAliveCount, self, KBFormatMB(KBPhysFootprintBytes()));
+#endif
   // 撤销删除是“上一段删除操作”的临时状态；键盘被系统回收/重建或跨页面回来时应当清空，避免误显示。
   [[KBBackspaceUndoManager shared] registerNonClearAction];
   [self setupUI];
@@ -149,12 +185,30 @@ static void KBSkinInstallNotificationCallback(CFNotificationCenterRef center,
   [self kb_applyDefaultSkinIfNeeded];
 }
 
+- (void)didReceiveMemoryWarning {
+  [super didReceiveMemoryWarning];
+  // 扩展进程内存上限较小：在系统发出内存警告时主动清理可重建的缓存，降低被系统杀死概率。
+  self.kb_cachedGradientImage = nil;
+  [self.kb_defaultGradientLayer removeFromSuperlayer];
+  self.kb_defaultGradientLayer = nil;
+  [[KBSkinManager shared] clearRuntimeImageCaches];
+  [[SDImageCache sharedImageCache] clearMemory];
+}
+
 - (void)viewWillAppear:(BOOL)animated {
   [super viewWillAppear:animated];
   // 进入/重新进入输入界面时，清理上一次会话残留的撤销状态与缓存，避免显示“撤销删除”但实际上已不可撤销。
   [[KBBackspaceUndoManager shared] registerNonClearAction];
   [[KBInputBufferManager shared] resetWithText:@""];
   [[KBLocalizationManager shared] reloadFromSharedStorageIfNeeded];
+  // 键盘再次出现时，恢复 HUD 容器与主题（viewDidDisappear 里可能已清理图片/缓存）。
+  [KBHUD setContainerView:self.view];
+  [self kb_ensureKeyBoardMainViewIfNeeded];
+  [self kb_applyTheme];
+#if DEBUG
+  NSLog(@"[Keyboard] viewWillAppear self=%p mem=%@",
+        self, KBFormatMB(KBPhysFootprintBytes()));
+#endif
   // 注意：微信/QQ 等宿主的 documentContext 可能是“截断窗口”，这里只更新
   // liveText，不要把它当作全文 manualSnapshot。
   [[KBInputBufferManager shared]
@@ -167,6 +221,17 @@ static void KBSkinInstallNotificationCallback(CFNotificationCenterRef center,
 - (void)viewWillDisappear:(BOOL)animated {
   [super viewWillDisappear:animated];
   [[KBBackspaceUndoManager shared] registerNonClearAction];
+  [self kb_releaseMemoryWhenKeyboardHidden];
+#if DEBUG
+  NSLog(@"[Keyboard] viewWillDisappear self=%p mem=%@",
+        self, KBFormatMB(KBPhysFootprintBytes()));
+#endif
+}
+
+- (void)viewDidDisappear:(BOOL)animated {
+  [super viewDidDisappear:animated];
+  // 再兜底一次，防止某些宿主只触发 willDisappear 而未触发 didDisappear。
+  [self kb_releaseMemoryWhenKeyboardHidden];
 }
 
 - (void)traitCollectionDidChange:(UITraitCollection *)previousTraitCollection {
@@ -196,9 +261,7 @@ static void KBSkinInstallNotificationCallback(CFNotificationCenterRef center,
   CGFloat portraitWidth = [self kb_portraitWidth];
   CGFloat keyboardHeight = [self kb_keyboardHeightForWidth:portraitWidth];
   CGFloat keyboardBaseHeight = [self kb_keyboardBaseHeightForWidth:portraitWidth];
-  CGFloat chatPanelHeight = [self kb_chatPanelHeightForWidth:portraitWidth];
   CGFloat screenWidth = CGRectGetWidth([UIScreen mainScreen].bounds);
-  CGFloat outerVerticalInset = KBFit(4.0f);
 
   NSLayoutConstraint *h =
       [self.view.heightAnchor constraintEqualToConstant:keyboardHeight];
@@ -231,12 +294,6 @@ static void KBSkinInstallNotificationCallback(CFNotificationCenterRef center,
   [self.bgImageView mas_makeConstraints:^(MASConstraintMaker *make) {
     make.edges.equalTo(self.contentView);
   }];
-  // 预置功能面板（默认隐藏），与键盘区域共享相同布局
-  self.functionView.hidden = YES;
-  [self.contentView addSubview:self.functionView];
-  [self.functionView mas_makeConstraints:^(MASConstraintMaker *make) {
-    make.edges.equalTo(self.contentView);
-  }];
 
   [self.contentView addSubview:self.keyBoardMainView];
   [self.keyBoardMainView mas_makeConstraints:^(MASConstraintMaker *make) {
@@ -246,15 +303,6 @@ static void KBSkinInstallNotificationCallback(CFNotificationCenterRef center,
         make.height.mas_equalTo(keyboardBaseHeight);
   }];
 
-  [self.contentView addSubview:self.chatPanelView];
-  [self.chatPanelView mas_makeConstraints:^(MASConstraintMaker *make) {
-    make.left.right.equalTo(self.contentView);
-    make.bottom.equalTo(self.keyBoardMainView.mas_top);
-    self.chatPanelHeightConstraint =
-        make.height.mas_equalTo(chatPanelHeight);
-  }];
-  self.chatPanelView.hidden = YES;
-
   // 初始隐藏，避免布局完成前闪烁
   self.contentView.hidden = YES;
 }
@@ -396,8 +444,14 @@ static void KBSkinInstallNotificationCallback(CFNotificationCenterRef center,
   // 简单显隐切换，复用相同的布局区域
   if (show) {
     [self showChatPanel:NO];
+    [self kb_ensureFunctionViewIfNeeded];
+  }
+  if (_functionView) {
+    _functionView.hidden = !show;
+  } else if (show) {
+    // ensure 后按理已存在；这里兜底一次，避免异常情况下状态不一致
+    self.functionView.hidden = NO;
   }
-  self.functionView.hidden = !show;
   self.keyBoardMainView.hidden = show;
 
   if (show) {
@@ -417,7 +471,9 @@ static void KBSkinInstallNotificationCallback(CFNotificationCenterRef center,
 
   // 可选：把当前显示的视图置顶，避免层级遮挡
   if (show) {
-    [self.contentView bringSubviewToFront:self.functionView];
+    if (_functionView) {
+      [self.contentView bringSubviewToFront:_functionView];
+    }
   } else {
     [self.contentView bringSubviewToFront:self.keyBoardMainView];
   }
@@ -492,10 +548,13 @@ static void KBSkinInstallNotificationCallback(CFNotificationCenterRef center,
   }
   self.chatPanelVisible = show;
   if (show) {
+    [self kb_ensureChatPanelViewIfNeeded];
     self.chatPanelView.hidden = NO;
     self.chatPanelView.alpha = 0.0;
     [self.contentView bringSubviewToFront:self.chatPanelView];
-    self.functionView.hidden = YES;
+    if (_functionView) {
+      _functionView.hidden = YES;
+    }
     [self hideSubscriptionPanel];
     [self showSettingView:NO];
     [UIView animateWithDuration:0.2
@@ -506,6 +565,11 @@ static void KBSkinInstallNotificationCallback(CFNotificationCenterRef center,
                      }
                      completion:nil];
   } else {
+    // 从未创建过聊天面板时，直接返回，避免 show/hide 触发额外内存分配
+    if (!_chatPanelView) {
+      [self kb_updateKeyboardLayoutIfNeeded];
+      return;
+    }
     [UIView animateWithDuration:0.18
         delay:0
         options:UIViewAnimationOptionCurveEaseIn
@@ -519,6 +583,114 @@ static void KBSkinInstallNotificationCallback(CFNotificationCenterRef center,
   [self kb_updateKeyboardLayoutIfNeeded];
 }
 
+// 延迟创建：仅在用户真正打开功能面板时才创建/布局，降低默认内存占用。
+- (void)kb_ensureFunctionViewIfNeeded {
+  if (_functionView && _functionView.superview) {
+    return;
+  }
+  KBFunctionView *v = self.functionView;
+  if (!v.superview) {
+    v.hidden = YES;
+    [self.contentView addSubview:v];
+    [v mas_makeConstraints:^(MASConstraintMaker *make) {
+      make.edges.equalTo(self.contentView);
+    }];
+  }
+}
+
+// 延迟创建：仅在用户打开聊天面板时才创建/布局。
+- (void)kb_ensureChatPanelViewIfNeeded {
+  if (_chatPanelView && _chatPanelView.superview) {
+    return;
+  }
+  CGFloat portraitWidth = [self kb_portraitWidth];
+  CGFloat chatPanelHeight = [self kb_chatPanelHeightForWidth:portraitWidth];
+  KBChatPanelView *v = self.chatPanelView;
+  if (!v.superview) {
+    [self.contentView addSubview:v];
+    [v mas_makeConstraints:^(MASConstraintMaker *make) {
+      make.left.right.equalTo(self.contentView);
+      make.bottom.equalTo(self.keyBoardMainView.mas_top);
+      self.chatPanelHeightConstraint =
+          make.height.mas_equalTo(chatPanelHeight);
+    }];
+    v.hidden = YES;
+  }
+}
+
+// 延迟创建：键盘主面板（按键区）在隐藏时会被释放；再次显示时需要重建。
+- (void)kb_ensureKeyBoardMainViewIfNeeded {
+  if (_keyBoardMainView && _keyBoardMainView.superview) {
+    return;
+  }
+  CGFloat portraitWidth = [self kb_portraitWidth];
+  CGFloat keyboardBaseHeight =
+      [self kb_keyboardBaseHeightForWidth:portraitWidth];
+  KBKeyBoardMainView *v = self.keyBoardMainView;
+  if (!v.superview) {
+    [self.contentView addSubview:v];
+    [v mas_makeConstraints:^(MASConstraintMaker *make) {
+      make.left.right.equalTo(self.contentView);
+      make.bottom.equalTo(self.contentView);
+      self.keyBoardMainHeightConstraint =
+          make.height.mas_equalTo(keyboardBaseHeight);
+    }];
+  }
+  [self.contentView bringSubviewToFront:v];
+}
+
+// 键盘隐藏时释放可重建资源（背景图/缓存/非必需面板），降低扩展内存峰值。
+- (void)kb_releaseMemoryWhenKeyboardHidden {
+  [KBHUD setContainerView:nil];
+  self.bgImageView.image = nil;
+  self.kb_cachedGradientImage = nil;
+  [self.kb_defaultGradientLayer removeFromSuperlayer];
+  self.kb_defaultGradientLayer = nil;
+  [[SDImageCache sharedImageCache] clearMemory];
+
+  // 聊天相关可能持有音频数据/临时文件，键盘隐藏时直接清空，避免累计占用。
+  if (self.chatAudioPlayer) {
+    [self.chatAudioPlayer stop];
+    self.chatAudioPlayer = nil;
+  }
+  if (_chatMessages.count > 0) {
+    NSString *tmpRoot = NSTemporaryDirectory();
+    for (KBChatMessage *msg in _chatMessages.copy) {
+      if (tmpRoot.length > 0 && msg.audioFilePath.length > 0 &&
+          [msg.audioFilePath hasPrefix:tmpRoot]) {
+        [[NSFileManager defaultManager] removeItemAtPath:msg.audioFilePath
+                                                   error:nil];
+      }
+    }
+    [_chatMessages removeAllObjects];
+  }
+
+  if (_keyBoardMainView) {
+    [_keyBoardMainView removeFromSuperview];
+    _keyBoardMainView = nil;
+  }
+  self.keyBoardMainHeightConstraint = nil;
+
+  if (_functionView) {
+    [_functionView removeFromSuperview];
+    _functionView = nil;
+  }
+  if (_chatPanelView) {
+    [_chatPanelView removeFromSuperview];
+    _chatPanelView = nil;
+  }
+  self.chatPanelVisible = NO;
+
+  if (_subscriptionView) {
+    [_subscriptionView removeFromSuperview];
+    _subscriptionView = nil;
+  }
+  if (_settingView) {
+    [_settingView removeFromSuperview];
+    _settingView = nil;
+  }
+}
+
 - (void)showSubscriptionPanel {
   // 1) 先判断权限：未开启“完全访问”则走引导逻辑
   if (![[KBFullAccessManager shared] hasFullAccess]) {
@@ -831,7 +1003,7 @@ static void KBSkinInstallNotificationCallback(CFNotificationCenterRef center,
 
 - (void)chatPanelViewDidTapClose:(KBChatPanelView *)view {
   // 清空 chatPanelView 内部的消息
-  [self.chatPanelView kb_reloadWithMessages:@[]];
+  [view kb_reloadWithMessages:@[]];
   if (self.chatAudioPlayer.isPlaying) {
     [self.chatAudioPlayer stop];
   }
@@ -1553,7 +1725,11 @@ static void KBSkinInstallNotificationCallback(CFNotificationCenterRef center,
       (__bridge const void *)(self),
       (__bridge CFStringRef)KBDarwinSkinInstallRequestNotification, NULL);
 #if DEBUG
-  NSLog(@"[Keyboard] KeyboardViewController dealloc");
+  if (_kb_debugDidCountAlive) {
+    sKBKeyboardVCAliveCount -= 1;
+  }
+  NSLog(@"[Keyboard] KeyboardViewController dealloc alive=%ld self=%p mem=%@",
+        (long)sKBKeyboardVCAliveCount, self, KBFormatMB(KBPhysFootprintBytes()));
 #endif
 }
 
@@ -1578,6 +1754,9 @@ static void KBSkinInstallNotificationCallback(CFNotificationCenterRef center,
   if (self.contentView.hidden) {
     self.contentView.hidden = NO;
   }
+  if (self.kb_defaultGradientLayer) {
+    self.kb_defaultGradientLayer.frame = self.bgImageView.bounds;
+  }
 }
 
 - (void)viewWillTransitionToSize:(CGSize)size
@@ -1611,93 +1790,133 @@ static void KBSkinInstallNotificationCallback(CFNotificationCenterRef center,
 #pragma mark - Theme
 
 - (void)kb_applyTheme {
-  KBSkinTheme *t = [KBSkinManager shared].current;
-  UIImage *img = [[KBSkinManager shared] currentBackgroundImage];
-  BOOL isDefaultTheme = [self kb_isDefaultKeyboardTheme:t];
-  BOOL isDarkMode = [self kb_isDarkModeActive];
-  CGSize size = self.bgImageView.bounds.size;
-  if (isDefaultTheme) {
-    if (isDarkMode) {
+  @autoreleasepool {
+    KBSkinTheme *t = [KBSkinManager shared].current;
+    UIImage *img = nil;
+    BOOL isDefaultTheme = [self kb_isDefaultKeyboardTheme:t];
+    BOOL isDarkMode = [self kb_isDarkModeActive];
+
+    NSString *skinId = t.skinId ?: @"";
+    NSString *themeKey =
+        [NSString stringWithFormat:@"%@|default=%d|dark=%d",
+                                   skinId, isDefaultTheme, isDarkMode];
+    BOOL themeChanged =
+        (self.kb_lastAppliedThemeKey.length == 0 ||
+         ![self.kb_lastAppliedThemeKey isEqualToString:themeKey]);
+    if (themeChanged) {
+      self.kb_lastAppliedThemeKey = themeKey;
+    }
+
+    CGSize size = self.bgImageView.bounds.size;
+    if (isDefaultTheme) {
+      if (isDarkMode) {
       // 暗黑模式：直接使用背景色，不使用图片渲染
       // 这样可以避免图片渲染时的色彩空间转换导致颜色不一致
       img = nil;
       self.bgImageView.image = nil;
+      [self.kb_defaultGradientLayer removeFromSuperlayer];
+      self.kb_defaultGradientLayer = nil;
       // 使用与系统键盘底部完全相同的颜色
       if (@available(iOS 13.0, *)) {
-        // iOS 系统键盘使用的实际颜色 (RGB: 44, 44, 46 in sRGB, 或 #2C2C2E)
-        // 但为了完美匹配，我们使用动态颜色并直接设置为背景
-        UIColor *kbBgColor =
-            [UIColor colorWithDynamicProvider:^UIColor *_Nonnull(
-                         UITraitCollection *_Nonnull traitCollection) {
-              if (traitCollection.userInterfaceStyle ==
-                  UIUserInterfaceStyleDark) {
-                // 暗黑模式下系统键盘实际背景色
-                return [UIColor colorWithRed:43.0 / 255.0
-                                       green:43.0 / 255.0
-                                        blue:43.0 / 255.0
-                                       alpha:1.0];
-              } else {
-                return [UIColor colorWithRed:209.0 / 255.0
-                                       green:211.0 / 255.0
-                                        blue:219.0 / 255.0
-                                       alpha:1.0];
-              }
-            }];
-        self.contentView.backgroundColor = kbBgColor;
-        self.bgImageView.backgroundColor = kbBgColor;
-      } else {
-        UIColor *darkColor = [UIColor colorWithRed:43.0 / 255.0
-                                             green:43.0 / 255.0
-                                              blue:43.0 / 255.0
-                                             alpha:1.0];
-        self.contentView.backgroundColor = darkColor;
-        self.bgImageView.backgroundColor = darkColor;
-      }
+          // iOS 系统键盘使用的实际颜色 (RGB: 44, 44, 46 in sRGB, 或 #2C2C2E)
+          // 但为了完美匹配，我们使用动态颜色并直接设置为背景
+          UIColor *kbBgColor =
+              [UIColor colorWithDynamicProvider:^UIColor *_Nonnull(
+                           UITraitCollection *_Nonnull traitCollection) {
+                if (traitCollection.userInterfaceStyle ==
+                    UIUserInterfaceStyleDark) {
+                  // 暗黑模式下系统键盘实际背景色
+                  return [UIColor colorWithRed:43.0 / 255.0
+                                         green:43.0 / 255.0
+                                          blue:43.0 / 255.0
+                                         alpha:1.0];
+                } else {
+                  return [UIColor colorWithRed:209.0 / 255.0
+                                         green:211.0 / 255.0
+                                          blue:219.0 / 255.0
+                                         alpha:1.0];
+                }
+              }];
+          self.contentView.backgroundColor = kbBgColor;
+          self.bgImageView.backgroundColor = kbBgColor;
+        } else {
+          UIColor *darkColor = [UIColor colorWithRed:43.0 / 255.0
+                                               green:43.0 / 255.0
+                                                blue:43.0 / 255.0
+                                               alpha:1.0];
+          self.contentView.backgroundColor = darkColor;
+          self.bgImageView.backgroundColor = darkColor;
+        }
     } else {
-      // 浅色模式：使用渐变图片
-      if (size.width <= 0 || size.height <= 0) {
-        [self.view layoutIfNeeded];
-        size = self.bgImageView.bounds.size;
+        // 浅色模式：使用渐变层（避免生成大位图导致内存上涨）
+        if (size.width <= 0 || size.height <= 0) {
+          [self.view layoutIfNeeded];
+          size = self.bgImageView.bounds.size;
+        }
+        if (size.width <= 0 || size.height <= 0) {
+          size = self.view.bounds.size;
+        }
+        if (size.width <= 0 || size.height <= 0) {
+          size = [UIScreen mainScreen].bounds.size;
+        }
+        UIColor *topColor = [UIColor colorWithHex:0xDEDFE4];
+        UIColor *bottomColor = [UIColor colorWithHex:0xD1D3DB];
+        UIColor *resolvedTopColor = topColor;
+        UIColor *resolvedBottomColor = bottomColor;
+        if (@available(iOS 13.0, *)) {
+          resolvedTopColor =
+              [topColor resolvedColorWithTraitCollection:self.traitCollection];
+          resolvedBottomColor = [bottomColor
+              resolvedColorWithTraitCollection:self.traitCollection];
+        }
+        CAGradientLayer *layer = self.kb_defaultGradientLayer;
+        if (!layer) {
+          layer = [CAGradientLayer layer];
+          layer.startPoint = CGPointMake(0.5, 0.0);
+          layer.endPoint = CGPointMake(0.5, 1.0);
+          [self.bgImageView.layer insertSublayer:layer atIndex:0];
+          self.kb_defaultGradientLayer = layer;
+        }
+        layer.colors = @[
+          (id)resolvedTopColor.CGColor,
+          (id)resolvedBottomColor.CGColor
+        ];
+        layer.frame = (CGRect){CGPointZero, size};
+        img = nil;
+        self.bgImageView.image = nil;
+        self.contentView.backgroundColor = [UIColor clearColor];
+        self.bgImageView.backgroundColor = [UIColor clearColor];
       }
-      if (size.width <= 0 || size.height <= 0) {
-        size = self.view.bounds.size;
-      }
-      if (size.width <= 0 || size.height <= 0) {
-        size = [UIScreen mainScreen].bounds.size;
-      }
-      UIColor *topColor = [UIColor colorWithHex:0xDEDFE4];
-      UIColor *bottomColor = [UIColor colorWithHex:0xD1D3DB];
-//      img = [self kb_defaultGradientImageWithSize:size
-//                                         topColor:topColor
-//                                      bottomColor:bottomColor];
+      NSLog(@"===");
+    } else {
+      // 自定义皮肤：清除背景色，使用皮肤图片
       self.contentView.backgroundColor = [UIColor clearColor];
       self.bgImageView.backgroundColor = [UIColor clearColor];
+      [self.kb_defaultGradientLayer removeFromSuperlayer];
+      self.kb_defaultGradientLayer = nil;
+      img = [[KBSkinManager shared] currentBackgroundImage];
     }
-    NSLog(@"===");
-  } else {
-    // 自定义皮肤：清除背景色，使用皮肤图片
-    self.contentView.backgroundColor = [UIColor clearColor];
-    self.bgImageView.backgroundColor = [UIColor clearColor];
-  }
-  NSLog(@"⌨️[Keyboard] apply theme id=%@ hasBg=%d", t.skinId, (img != nil));
-  [self kb_logSkinDiagnosticsWithTheme:t backgroundImage:img];
-  self.bgImageView.image = img;
+    NSLog(@"⌨️[Keyboard] apply theme id=%@ hasBg=%d", t.skinId, (img != nil));
+    [self kb_logSkinDiagnosticsWithTheme:t backgroundImage:img];
+    self.bgImageView.image = img;
 
-//  [self.chatPanelView kb_setBackgroundImage:img];
-  BOOL hasImg = (img != nil);
-  // 触发键区按主题重绘
-  if ([self.keyBoardMainView respondsToSelector:@selector(kb_applyTheme)]) {
+    // 触发键区按主题重绘
+    if (themeChanged &&
+        [self.keyBoardMainView respondsToSelector:@selector(kb_applyTheme)]) {
 // method declared in KBKeyBoardMainView.h
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Warc-performSelector-leaks"
-    [self.keyBoardMainView performSelector:@selector(kb_applyTheme)];
+      [self.keyBoardMainView performSelector:@selector(kb_applyTheme)];
 #pragma clang diagnostic pop
-  }
-  if ([self.functionView respondsToSelector:@selector(kb_applyTheme)]) {
+    }
+    // 注意：这里不能直接访问 self.functionView，否则会导致功能面板提前创建，占用内存。
+    if (themeChanged && _functionView &&
+        [_functionView respondsToSelector:@selector(kb_applyTheme)]) {
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Warc-performSelector-leaks"
-    [self.functionView performSelector:@selector(kb_applyTheme)];
+      [_functionView performSelector:@selector(kb_applyTheme)];
 #pragma clang diagnostic pop
+    }
   }
 }
 
diff --git a/CustomKeyboard/View/KBKeyboardView.m b/CustomKeyboard/View/KBKeyboardView.m
index 5936411..82bd326 100644
--- a/CustomKeyboard/View/KBKeyboardView.m
+++ b/CustomKeyboard/View/KBKeyboardView.m
@@ -49,7 +49,6 @@ static const CGFloat kKBLettersRow2EdgeSpacerMultiplier = 0.5;
         self.layoutConfig = [KBKeyboardLayoutConfig sharedConfig];
         self.backspaceHandler = [[KBBackspaceLongPressHandler alloc] initWithContainerView:self];
         [self buildBase];
-        [self reloadKeys];
     }
     return self;
 }
diff --git a/CustomKeyboard/View/KBToolBar.m b/CustomKeyboard/View/KBToolBar.m
index 9b8d8f2..408dc71 100644
--- a/CustomKeyboard/View/KBToolBar.m
+++ b/CustomKeyboard/View/KBToolBar.m
@@ -9,6 +9,7 @@
 #import "KBResponderUtils.h" // 查找 UIInputViewController，用于系统切换输入法
 #import "KBBackspaceUndoManager.h"
 #import "KBSkinManager.h"
+#import <ImageIO/ImageIO.h>
 
 @interface KBToolBar ()
 @property (nonatomic, strong) UIView *leftContainer;
@@ -20,6 +21,8 @@
 @property (nonatomic, assign) BOOL kbNeedsInputModeSwitchKey;
 @property (nonatomic, assign) BOOL kbUndoVisible;
 @property (nonatomic, assign) BOOL kbAvatarVisible;
+@property (nonatomic, copy, nullable) NSString *kb_cachedPersonaCoverPath;
+@property (nonatomic, strong, nullable) UIImage *kb_cachedPersonaCoverImage;
 @end
 
 @implementation KBToolBar
@@ -256,10 +259,41 @@
         [[containerURL path] stringByAppendingPathComponent:@"persona_cover.jpg"];
     if (imagePath.length == 0 ||
         ![[NSFileManager defaultManager] fileExistsAtPath:imagePath]) {
+        self.kb_cachedPersonaCoverPath = nil;
+        self.kb_cachedPersonaCoverImage = nil;
         return nil;
     }
 
-    return [UIImage imageWithContentsOfFile:imagePath];
+    if (self.kb_cachedPersonaCoverImage &&
+        [self.kb_cachedPersonaCoverPath isEqualToString:imagePath]) {
+        return self.kb_cachedPersonaCoverImage;
+    }
+
+    // 头像仅 40pt，直接按像素上限缩略解码，避免每次显示键盘都 full decode 一张大 JPG 顶爆扩展内存。
+    NSUInteger maxPixel = 256;
+    NSURL *url = [NSURL fileURLWithPath:imagePath];
+    CGImageSourceRef source = CGImageSourceCreateWithURL((__bridge CFURLRef)url, NULL);
+    if (!source) {
+        return nil;
+    }
+    NSDictionary *opts = @{
+        (__bridge id)kCGImageSourceCreateThumbnailFromImageAlways : @YES,
+        (__bridge id)kCGImageSourceCreateThumbnailWithTransform : @YES,
+        (__bridge id)kCGImageSourceThumbnailMaxPixelSize : @(maxPixel),
+    };
+    CGImageRef cg = CGImageSourceCreateThumbnailAtIndex(source, 0, (__bridge CFDictionaryRef)opts);
+    CFRelease(source);
+    if (!cg) {
+        return nil;
+    }
+    UIImage *img = [UIImage imageWithCGImage:cg
+                                       scale:[UIScreen mainScreen].scale
+                                 orientation:UIImageOrientationUp];
+    CGImageRelease(cg);
+
+    self.kb_cachedPersonaCoverPath = imagePath;
+    self.kb_cachedPersonaCoverImage = img;
+    return img;
 }
 
 #pragma mark - Actions
diff --git a/Shared/KBSkinManager.h b/Shared/KBSkinManager.h
index 5eb398f..82f9931 100644
--- a/Shared/KBSkinManager.h
+++ b/Shared/KBSkinManager.h
@@ -54,6 +54,9 @@ extern NSString * const KBDarwinSkinChanged;         // cross-process
 /// 当前背景图片（若存在）
 - (nullable UIImage *)currentBackgroundImage;
 
+/// 清理运行时图片缓存（内存缓存）。键盘扩展接近内存上限时可主动调用。
+- (void)clearRuntimeImageCaches;
+
 /// 当前主题下，指定按键标识的文字是否应被隐藏（例如图标里已包含字母）
 - (BOOL)shouldHideKeyTextForIdentifier:(nullable NSString *)identifier;
 
diff --git a/Shared/KBSkinManager.m b/Shared/KBSkinManager.m
index ce973f6..d21a9d3 100644
--- a/Shared/KBSkinManager.m
+++ b/Shared/KBSkinManager.m
@@ -4,6 +4,7 @@
 
 #import "KBSkinManager.h"
 #import "KBConfig.h"
+#import <ImageIO/ImageIO.h>
 
 NSString * const KBSkinDidChangeNotification = @"KBSkinDidChangeNotification";
 NSString * const KBDarwinSkinChanged = @"com.loveKey.nyx.skin.changed";
@@ -59,10 +60,45 @@ static NSString * const kKBSkinThemeStoreKey = @"KBSkinThemeCurrent";
 
 @interface KBSkinManager ()
 @property (atomic, strong, readwrite) KBSkinTheme *current;
+@property (nonatomic, strong) NSCache<NSString *, UIImage *> *kb_fileImageCache;
+@property (nonatomic, copy, nullable) NSString *kb_cachedBgSkinId;
+@property (nonatomic, assign) BOOL kb_cachedBgResolved;
+@property (nonatomic, strong, nullable) UIImage *kb_cachedBgImage;
 @end
 
 @implementation KBSkinManager
 
+/// 从文件路径解码图片，并按 maxPixel 限制最长边像素（避免加载超大背景图导致键盘扩展内存飙升）。
++ (nullable UIImage *)kb_imageAtPath:(NSString *)path maxPixel:(NSUInteger)maxPixel {
+    if (path.length == 0) return nil;
+    NSURL *url = [NSURL fileURLWithPath:path];
+    CGImageSourceRef source = CGImageSourceCreateWithURL((__bridge CFURLRef)url, NULL);
+    if (!source) return nil;
+    NSDictionary *opts = @{
+        (__bridge id)kCGImageSourceCreateThumbnailFromImageAlways : @YES,
+        (__bridge id)kCGImageSourceCreateThumbnailWithTransform : @YES,
+        (__bridge id)kCGImageSourceThumbnailMaxPixelSize : @(MAX(1, (NSInteger)maxPixel)),
+    };
+    CGImageRef cg = CGImageSourceCreateThumbnailAtIndex(source, 0, (__bridge CFDictionaryRef)opts);
+    CFRelease(source);
+    if (!cg) return nil;
+    UIImage *img = [UIImage imageWithCGImage:cg scale:[UIScreen mainScreen].scale orientation:UIImageOrientationUp];
+    CGImageRelease(cg);
+    return img;
+}
+
+static inline NSUInteger KBApproxImageCostBytes(UIImage *img) {
+    if (!img) return 0;
+    CGFloat scale = img.scale > 0 ? img.scale : [UIScreen mainScreen].scale;
+    CGSize s = img.size;
+    double px = (double)s.width * scale * (double)s.height * scale;
+    if (px <= 0) return 0;
+    // RGBA 4 bytes/pixel
+    double cost = px * 4.0;
+    if (cost > (double)NSUIntegerMax) return NSUIntegerMax;
+    return (NSUInteger)cost;
+}
+
 /// 返回所有可能的皮肤根目录（优先 App Group，其次当前进程的 Caches）。
 + (NSArray<NSString *> *)kb_candidateBaseRoots {
     NSMutableArray<NSString *> *roots = [NSMutableArray array];
@@ -104,6 +140,14 @@ static NSString * const kKBSkinThemeStoreKey = @"KBSkinThemeCurrent";
 
 - (instancetype)init {
     if (self = [super init]) {
+        _kb_fileImageCache = [NSCache new];
+        // 键盘扩展内存上限较小，缓存要保守一些；主 App 也共用该实现但不会出问题。
+        // iPad 的键盘背景可能更大，适当放宽。
+        if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) {
+            _kb_fileImageCache.totalCostLimit = 24 * 1024 * 1024;
+        } else {
+            _kb_fileImageCache.totalCostLimit = 12 * 1024 * 1024;
+        }
         KBSkinTheme *t = [self p_loadFromStore];
         // 若存储中的皮肤在 App Group 中找不到对应资源目录（如首次安装 / 已被清理），则回退到默认皮肤。
         if (!t || ![self.class kb_hasAssetsForSkinId:t.skinId]) {
@@ -170,6 +214,7 @@ static void KBSkinDarwinCallback(CFNotificationCenterRef center, void *observer,
 - (BOOL)applyTheme:(KBSkinTheme *)theme {
     if (!theme) return NO;
     NSLog(@"🎨[SkinManager] apply theme id=%@ name=%@", theme.skinId, theme.name);
+    [self clearRuntimeImageCaches];
     // 将主题写入 App Group 存储（失败也不影响本次进程内的使用）
     [self p_saveToStore:theme];
     // 始终更新当前主题并广播通知，确保当前进程和扩展之间保持同步。
@@ -187,6 +232,15 @@ static void KBSkinDarwinCallback(CFNotificationCenterRef center, void *observer,
     [self applyTheme:[self.class defaultTheme]];
 }
 
+- (void)clearRuntimeImageCaches {
+    @synchronized (self) {
+        [self.kb_fileImageCache removeAllObjects];
+        self.kb_cachedBgSkinId = nil;
+        self.kb_cachedBgResolved = NO;
+        self.kb_cachedBgImage = nil;
+    }
+}
+
 - (BOOL)applyImageSkinWithData:(NSData *)imageData skinId:(NSString *)skinId name:(NSString *)name {
     // 仅作为“存在背景图”的标记使用：图像文件本身存放在 App Group 容器
     // Skins/<skinId>/background.png 中，这里不再把二进制图片写入 Keychain，
@@ -216,20 +270,52 @@ static void KBSkinDarwinCallback(CFNotificationCenterRef center, void *observer,
     NSString *skinId = self.current.skinId;
     if (skinId.length == 0) return nil;
 
+    // 同一个 skinId 在键盘的生命周期内会被频繁读取；缓存一份避免反复解码导致内存上涨。
+    @synchronized (self) {
+        if (self.kb_cachedBgResolved && [self.kb_cachedBgSkinId isEqualToString:skinId]) {
+            return self.kb_cachedBgImage;
+        }
+    }
+
     NSArray<NSString *> *roots = [self.class kb_candidateBaseRoots];
     NSFileManager *fm = [NSFileManager defaultManager];
     NSString *relative = [NSString stringWithFormat:@"Skins/%@/background.png", skinId];
 
+    // 背景图通常远大于键盘实际显示区域，按像素上限做缩略解码，显著降低扩展内存占用。
+    NSUInteger maxPixel = (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) ? 2048 : 1024;
     for (NSString *base in roots) {
         NSString *bgPath = [[base stringByAppendingPathComponent:relative] stringByStandardizingPath];
         BOOL isDir = NO;
         if (![fm fileExistsAtPath:bgPath isDirectory:&isDir] || isDir) {
             continue;
         }
-        NSData *data = [NSData dataWithContentsOfFile:bgPath];
-        if (data.length == 0) continue;
-        UIImage *img = [UIImage imageWithData:data scale:[UIScreen mainScreen].scale];
-        if (img) return img;
+        NSString *cacheKey = [NSString stringWithFormat:@"bg|%@", bgPath];
+        UIImage *cached = [self.kb_fileImageCache objectForKey:cacheKey];
+        if (cached) {
+            @synchronized (self) {
+                self.kb_cachedBgSkinId = skinId;
+                self.kb_cachedBgResolved = YES;
+                self.kb_cachedBgImage = cached;
+            }
+            return cached;
+        }
+
+        UIImage *img = [self.class kb_imageAtPath:bgPath maxPixel:maxPixel];
+        if (img) {
+            NSUInteger cost = KBApproxImageCostBytes(img);
+            [self.kb_fileImageCache setObject:img forKey:cacheKey cost:cost];
+            @synchronized (self) {
+                self.kb_cachedBgSkinId = skinId;
+                self.kb_cachedBgResolved = YES;
+                self.kb_cachedBgImage = img;
+            }
+            return img;
+        }
+    }
+    @synchronized (self) {
+        self.kb_cachedBgSkinId = skinId;
+        self.kb_cachedBgResolved = YES;
+        self.kb_cachedBgImage = nil;
     }
     return nil;
 }
@@ -314,7 +400,13 @@ static void KBSkinDarwinCallback(CFNotificationCenterRef center, void *observer,
                 if (![fm fileExistsAtPath:fullPath isDirectory:&isDir] || isDir) {
                     continue;
                 }
-                UIImage *img = [UIImage imageWithContentsOfFile:fullPath];
+                NSString *cacheKey = [NSString stringWithFormat:@"icon|%@", fullPath];
+                UIImage *img = [self.kb_fileImageCache objectForKey:cacheKey];
+                if (img) return img;
+                img = [UIImage imageWithContentsOfFile:fullPath];
+                if (img) {
+                    [self.kb_fileImageCache setObject:img forKey:cacheKey cost:KBApproxImageCostBytes(img)];
+                }
                 if (img) return img;
             }
 #if DEBUG
@@ -351,7 +443,13 @@ static void KBSkinDarwinCallback(CFNotificationCenterRef center, void *observer,
             NSString *fullPath = [[base stringByAppendingPathComponent:relative] stringByStandardizingPath];
             BOOL isDir = NO;
             if ([fm fileExistsAtPath:fullPath isDirectory:&isDir] && !isDir) {
-                UIImage *img = [UIImage imageWithContentsOfFile:fullPath];
+                NSString *cacheKey = [NSString stringWithFormat:@"icon|%@", fullPath];
+                UIImage *img = [self.kb_fileImageCache objectForKey:cacheKey];
+                if (img) return img;
+                img = [UIImage imageWithContentsOfFile:fullPath];
+                if (img) {
+                    [self.kb_fileImageCache setObject:img forKey:cacheKey cost:KBApproxImageCostBytes(img)];
+                }
                 if (img) return img;
             }
         }
@@ -363,7 +461,13 @@ static void KBSkinDarwinCallback(CFNotificationCenterRef center, void *observer,
         NSString *fullPath = [[base stringByAppendingPathComponent:relative] stringByStandardizingPath];
         BOOL isDir = NO;
         if ([fm fileExistsAtPath:fullPath isDirectory:&isDir] && !isDir) {
-            UIImage *img = [UIImage imageWithContentsOfFile:fullPath];
+            NSString *cacheKey = [NSString stringWithFormat:@"icon|%@", fullPath];
+            UIImage *img = [self.kb_fileImageCache objectForKey:cacheKey];
+            if (img) return img;
+            img = [UIImage imageWithContentsOfFile:fullPath];
+            if (img) {
+                [self.kb_fileImageCache setObject:img forKey:cacheKey cost:KBApproxImageCostBytes(img)];
+            }
             if (img) return img;
         }
     }
@@ -449,6 +553,7 @@ static void KBSkinDarwinCallback(CFNotificationCenterRef center, void *observer,
     if (!t || ![self.class kb_hasAssetsForSkinId:t.skinId]) {
         t = [self.class defaultTheme];
     }
+    [self clearRuntimeImageCaches];
     self.current = t;
     if (broadcast) {
         [[NSNotificationCenter defaultCenter] postNotificationName:KBSkinDidChangeNotification object:nil];