diff --git a/CustomKeyboard/View/KBStreamTextView.m b/CustomKeyboard/View/KBStreamTextView.m
index 0f50d1a..502a961 100644
--- a/CustomKeyboard/View/KBStreamTextView.m
+++ b/CustomKeyboard/View/KBStreamTextView.m
@@ -16,6 +16,8 @@
 @property (nonatomic, strong) UIScrollView *scrollView;
 // 已创建的标签集合（顺序即显示顺序）
 @property (nonatomic, strong) NSMutableArray<UILabel *> *labels;
+// 与 labels 对应的分割线
+@property (nonatomic, strong) NSMutableArray<UIView *> *separatorLines;
 // 每一段对应的“原始文本”（不含前缀编号），与 labels 一一对应
 @property (nonatomic, strong) NSMutableArray<NSString *> *segmentTexts;
 // 文本缓冲：保存尚未遇到分隔符的尾部文本
@@ -23,6 +25,10 @@
 
 @end
 
+static const CGFloat kKBStreamSeparatorHeight = 0.5f;
+static const CGFloat kKBStreamSeparatorSpacingAbove = 5.0f;
+static const CGFloat kKBStreamSeparatorSpacingBelow = 10.0f;
+
 @implementation KBStreamTextView
 
 - (instancetype)initWithFrame:(CGRect)frame {
@@ -47,6 +53,7 @@
     _contentHorizontalPadding = 12.0;
     _interItemSpacing = 5.0; // 标签之间的垂直间距 5pt
     _labels = [NSMutableArray array];
+    _separatorLines = [NSMutableArray array];
     _segmentTexts = [NSMutableArray array];
     _buffer = @"";
     _shouldTrimSegments = YES;
@@ -147,6 +154,10 @@ static inline NSString *KBTrimRight(NSString *s) {
         [lbl removeFromSuperview];
     }
     [self.labels removeAllObjects];
+    for (UIView *line in self.separatorLines) {
+        [line removeFromSuperview];
+    }
+    [self.separatorLines removeAllObjects];
      [self.segmentTexts removeAllObjects];
     self.buffer = @"";
     self.scrollView.contentSize = CGSizeMake(self.bounds.size.width, 0);
@@ -170,8 +181,13 @@ static inline NSString *KBTrimRight(NSString *s) {
     UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleLabelTap:)];
     [label addGestureRecognizer:tap];
 
+    UIView *separator = [self buildSeparatorLine];
+    [self.scrollView addSubview:separator];
+    [self.separatorLines addObject:separator];
+
     [self.scrollView addSubview:label];
     [self.labels addObject:label];
+
     // 维护原始文本数组，与 labels 一一对应
     if (self.segmentTexts.count <= idx) {
         while (self.segmentTexts.count < idx) { [self.segmentTexts addObject:@""]; }
@@ -208,6 +224,10 @@ static inline NSString *KBTrimRight(NSString *s) {
     UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleLabelTap:)];
     [label addGestureRecognizer:tap];
 
+    UIView *separator = [self buildSeparatorLine];
+    [self.scrollView addSubview:separator];
+    [self.separatorLines addObject:separator];
+
     [self.scrollView addSubview:label];
     [self.labels addObject:label];
     // 保证 segmentTexts 与 labels 对齐
@@ -264,13 +284,22 @@ static inline NSString *KBTrimRight(NSString *s) {
         CGSize size = [self sizeForText:label.text font:label.font maxWidth:maxLabelWidth];
         label.frame = CGRectMake(x, y, maxLabelWidth, size.height);
         y += size.height;
-        // 标签间距：下一个标签位于上一个标签下方 5pt
+
+        UIView *separator = (idx < self.separatorLines.count) ? self.separatorLines[idx] : nil;
+        CGFloat separatorTop = y + kKBStreamSeparatorSpacingAbove;
+        if (separator) {
+            separator.hidden = NO;
+            separator.frame = CGRectMake(x, separatorTop, maxLabelWidth, kKBStreamSeparatorHeight);
+        }
+        y = separatorTop + kKBStreamSeparatorHeight;
+
         if (idx + 1 < self.labels.count) {
-            y += self.interItemSpacing;
+            y += kKBStreamSeparatorSpacingBelow;
         }
     }
 
-    CGFloat contentHeight = MAX(y + self.interItemSpacing, self.bounds.size.height + 1.0);
+    y += self.interItemSpacing;
+    CGFloat contentHeight = MAX(y, self.bounds.size.height + 1.0);
     self.scrollView.contentSize = CGSizeMake(width, contentHeight);
 }
 
@@ -316,8 +345,14 @@ static inline NSString *KBTrimRight(NSString *s) {
     UIInputViewController *ivc = KBFindInputViewController(self);
     if (ivc) {
         id<UITextDocumentProxy> proxy = ivc.textDocumentProxy;
-        if (rawText.length > 0 && [proxy conformsToProtocol:@protocol(UITextDocumentProxy)]) {
-            [proxy insertText:rawText];
+        if ([proxy conformsToProtocol:@protocol(UITextDocumentProxy)]) {
+            NSString *context = proxy.documentContextBeforeInput ?: @"";
+            for (NSUInteger i = 0; i < context.length; i++) {
+                [proxy deleteBackward];
+            }
+            if (rawText.length > 0) {
+                [proxy insertText:rawText];
+            }
         }
     }
 }
@@ -358,4 +393,11 @@ static inline NSString *KBTrimRight(NSString *s) {
     label.text = [self displayTextForSegmentIndex:idx content:body];
 }
 
+- (UIView *)buildSeparatorLine {
+    UIView *line = [[UIView alloc] initWithFrame:CGRectZero];
+    line.backgroundColor = [UIColor colorWithHex:0x02BEAC];
+    line.hidden = YES;
+    return line;
+}
+
 @end