NotepadWindow.xaml

<?xml version="1.0" encoding="utf-8"?>
<Window
    x:Class="NoteUI.NotepadWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:ctk="using:CommunityToolkit.WinUI.Controls"
    Title="Bloc-notes">

    <Grid x:Name="RootGrid" Background="Transparent">
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="*"/>
            <RowDefinition Height="Auto"/>
        </Grid.RowDefinitions>

        <!-- Row 0: Title bar with integrated tabs -->
        <Grid x:Name="TitleBar" Grid.Row="0" Height="40">
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="*"/>
                <ColumnDefinition Width="Auto"/>
            </Grid.ColumnDefinitions>

            <!-- Tab strip in title bar -->
            <ScrollViewer Grid.Column="0" Margin="4,0,0,0"
                          HorizontalScrollBarVisibility="Auto"
                          VerticalScrollBarVisibility="Disabled"
                          HorizontalScrollMode="Enabled"
                          VerticalScrollMode="Disabled">
                <StackPanel x:Name="TabStrip" Orientation="Horizontal" Spacing="1"
                            VerticalAlignment="Bottom"/>
            </ScrollViewer>

            <TextBlock x:Name="TitleText" Visibility="Collapsed"/>

            <StackPanel Grid.Column="1" Orientation="Horizontal"
                        VerticalAlignment="Center" Spacing="0" Margin="0,0,4,0">
                <Button x:Name="PinButton" Background="Transparent" BorderThickness="0"
                        Padding="8,6" Click="Pin_Click">
                    <FontIcon x:Name="PinIcon" Glyph="&#xE718;" FontSize="12"/>
                </Button>
                <Button x:Name="NpCloseButton" Background="Transparent" BorderThickness="0"
                        Padding="8,6" Click="Close_Click">
                    <FontIcon Glyph="&#xE711;" FontSize="12"/>
                </Button>
            </StackPanel>

            <!-- Drag bar: rendered last = top z-order, thin strip at top of title bar -->
            <Grid x:Name="DragBar" Background="Transparent"
                  Grid.ColumnSpan="2"
                  Height="12" VerticalAlignment="Top"
                  PointerPressed="DragBar_PointerPressed"
                  PointerMoved="DragBar_PointerMoved"
                  PointerReleased="DragBar_PointerReleased"/>
        </Grid>

        <!-- Row 1: Menu bar -->
        <MenuBar Grid.Row="1" Padding="2,0">
            <MenuBarItem x:Name="FileMenu" Title="_">
                <MenuFlyoutItem x:Name="MenuNew" Click="New_Click"
                                KeyboardAcceleratorTextOverride="Ctrl+N">
                    <MenuFlyoutItem.KeyboardAccelerators>
                        <KeyboardAccelerator Modifiers="Control" Key="N"/>
                    </MenuFlyoutItem.KeyboardAccelerators>
                </MenuFlyoutItem>
                <MenuFlyoutItem x:Name="MenuNewTab" Click="NewTab_Click"
                                KeyboardAcceleratorTextOverride="Ctrl+T">
                    <MenuFlyoutItem.KeyboardAccelerators>
                        <KeyboardAccelerator Modifiers="Control" Key="T"/>
                    </MenuFlyoutItem.KeyboardAccelerators>
                </MenuFlyoutItem>
                <MenuFlyoutItem x:Name="MenuCloseTab" Click="CloseTab_Click"
                                KeyboardAcceleratorTextOverride="Ctrl+W">
                    <MenuFlyoutItem.KeyboardAccelerators>
                        <KeyboardAccelerator Modifiers="Control" Key="W"/>
                    </MenuFlyoutItem.KeyboardAccelerators>
                </MenuFlyoutItem>
                <MenuFlyoutSeparator/>
                <MenuFlyoutItem x:Name="MenuOpen" Click="Open_Click"
                                KeyboardAcceleratorTextOverride="Ctrl+O">
                    <MenuFlyoutItem.KeyboardAccelerators>
                        <KeyboardAccelerator Modifiers="Control" Key="O"/>
                    </MenuFlyoutItem.KeyboardAccelerators>
                </MenuFlyoutItem>
                <MenuFlyoutItem x:Name="MenuSave" Click="Save_Click"
                                KeyboardAcceleratorTextOverride="Ctrl+S">
                    <MenuFlyoutItem.KeyboardAccelerators>
                        <KeyboardAccelerator Modifiers="Control" Key="S"/>
                    </MenuFlyoutItem.KeyboardAccelerators>
                </MenuFlyoutItem>
                <MenuFlyoutItem x:Name="MenuSaveAs" Click="SaveAs_Click"
                                KeyboardAcceleratorTextOverride="Ctrl+Shift+S">
                    <MenuFlyoutItem.KeyboardAccelerators>
                        <KeyboardAccelerator Modifiers="Control,Shift" Key="S"/>
                    </MenuFlyoutItem.KeyboardAccelerators>
                </MenuFlyoutItem>
                <MenuFlyoutSeparator/>
                <MenuFlyoutItem x:Name="MenuSaveToNotes" Click="SaveToNotes_Click"/>
                <MenuFlyoutSeparator/>
                <MenuFlyoutItem x:Name="MenuOpenNote" Click="OpenNote_Click"/>
                <MenuFlyoutSeparator/>
                <MenuFlyoutItem x:Name="MenuClose" Click="CloseMenu_Click"/>
            </MenuBarItem>

            <MenuBarItem x:Name="EditMenu" Title="_">
                <MenuFlyoutItem x:Name="MenuUndo" Click="Undo_Click"
                                KeyboardAcceleratorTextOverride="Ctrl+Z"/>
                <MenuFlyoutItem x:Name="MenuRedo" Click="Redo_Click"
                                KeyboardAcceleratorTextOverride="Ctrl+Y"/>
                <MenuFlyoutSeparator/>
                <MenuFlyoutItem x:Name="MenuCut" Click="Cut_Click"
                                KeyboardAcceleratorTextOverride="Ctrl+X"/>
                <MenuFlyoutItem x:Name="MenuCopy" Click="Copy_Click"
                                KeyboardAcceleratorTextOverride="Ctrl+C"/>
                <MenuFlyoutItem x:Name="MenuPaste" Click="Paste_Click"
                                KeyboardAcceleratorTextOverride="Ctrl+V"/>
                <MenuFlyoutSeparator/>
                <MenuFlyoutItem x:Name="MenuSelectAll" Click="SelectAll_Click"
                                KeyboardAcceleratorTextOverride="Ctrl+A"/>
                <MenuFlyoutSeparator/>
                <MenuFlyoutItem x:Name="MenuDateTime" Click="InsertDateTime_Click"
                                KeyboardAcceleratorTextOverride="F5">
                    <MenuFlyoutItem.KeyboardAccelerators>
                        <KeyboardAccelerator Key="F5"/>
                    </MenuFlyoutItem.KeyboardAccelerators>
                </MenuFlyoutItem>
                <MenuFlyoutSeparator/>
                <MenuFlyoutItem x:Name="MenuSnippet" Click="Snippet_Click">
                    <MenuFlyoutItem.Icon>
                        <FontIcon Glyph="&#xE943;"/>
                    </MenuFlyoutItem.Icon>
                </MenuFlyoutItem>
            </MenuBarItem>

            <MenuBarItem x:Name="ViewMenu" Title="_">
                <ToggleMenuFlyoutItem x:Name="WordWrapItem"
                                      IsChecked="True"
                                      Click="WordWrap_Click"/>
                <MenuFlyoutSeparator/>
                <MenuFlyoutItem x:Name="MenuZoomIn" Click="ZoomIn_Click"
                                KeyboardAcceleratorTextOverride="Ctrl++"/>
                <MenuFlyoutItem x:Name="MenuZoomOut" Click="ZoomOut_Click"
                                KeyboardAcceleratorTextOverride="Ctrl+-"/>
                <MenuFlyoutItem x:Name="MenuZoomDefault" Click="ZoomReset_Click"
                                KeyboardAcceleratorTextOverride="Ctrl+0"/>
                <MenuFlyoutSeparator/>
                <ToggleMenuFlyoutItem x:Name="AutoResizeItem"
                                      IsChecked="False"
                                      Click="AutoResize_Click"/>
                <MenuFlyoutSeparator/>
                <ToggleMenuFlyoutItem x:Name="SplitViewItem"
                                      IsChecked="False"
                                      Click="SplitView_Click"/>
                <MenuFlyoutSeparator/>
                <ToggleMenuFlyoutItem x:Name="FocusModeItem"
                                      IsChecked="False"
                                      Click="FocusMode_Click"
                                      KeyboardAcceleratorTextOverride="F11">
                    <ToggleMenuFlyoutItem.KeyboardAccelerators>
                        <KeyboardAccelerator Key="F11"/>
                    </ToggleMenuFlyoutItem.KeyboardAccelerators>
                </ToggleMenuFlyoutItem>
            </MenuBarItem>
        </MenuBar>

        <!-- Row 2: Formatting toolbar -->
        <Border Grid.Row="2"
                BorderBrush="{ThemeResource DividerStrokeColorDefaultBrush}"
                BorderThickness="0,0,0,1"
                Padding="8,4">
            <StackPanel Orientation="Horizontal" Spacing="2" VerticalAlignment="Center">

                <!-- Heading dropdown -->
                <DropDownButton x:Name="HeadingButton" Content="Normal"
                                Padding="10,4" FontSize="12" CornerRadius="4">
                    <DropDownButton.Flyout>
                        <MenuFlyout Placement="Bottom">
                            <MenuFlyoutItem x:Name="MenuHeadingNormal" Click="Heading_Normal_Click"/>
                            <MenuFlyoutItem x:Name="MenuHeadingH1" Click="Heading_H1_Click"/>
                            <MenuFlyoutItem x:Name="MenuHeadingH2" Click="Heading_H2_Click"/>
                            <MenuFlyoutItem x:Name="MenuHeadingH3" Click="Heading_H3_Click"/>
                        </MenuFlyout>
                    </DropDownButton.Flyout>
                </DropDownButton>

                <!-- Separator -->
                <Border Width="1"
                        Background="{ThemeResource DividerStrokeColorDefaultBrush}"
                        Margin="4,2" VerticalAlignment="Stretch"/>

                <!-- Bold -->
                <ToggleButton x:Name="BoldButton"
                              Padding="10,4" CornerRadius="4"
                              Click="Bold_Click">
                    <TextBlock Text="B" FontWeight="Bold" FontSize="13"/>
                </ToggleButton>

                <!-- Italic -->
                <ToggleButton x:Name="ItalicButton"
                              Padding="10,4" CornerRadius="4"
                              Click="Italic_Click">
                    <TextBlock Text="I" FontStyle="Italic" FontSize="13"/>
                </ToggleButton>

                <!-- Strikethrough -->
                <ToggleButton x:Name="StrikethroughButton"
                              Padding="10,4" CornerRadius="4"
                              Click="Strikethrough_Click">
                    <TextBlock Text="S" TextDecorations="Strikethrough" FontSize="13"/>
                </ToggleButton>

                <!-- Underline -->
                <ToggleButton x:Name="UnderlineButton"
                              Padding="10,4" CornerRadius="4"
                              Click="Underline_Click">
                    <TextBlock Text="U" TextDecorations="Underline" FontSize="13"/>
                </ToggleButton>

                <!-- Separator -->
                <Border Width="1"
                        Background="{ThemeResource DividerStrokeColorDefaultBrush}"
                        Margin="4,2" VerticalAlignment="Stretch"/>

                <!-- Link -->
                <Button x:Name="LinkButton"
                        Padding="10,4" CornerRadius="4"
                        Click="Link_Click">
                    <FontIcon Glyph="&#xE71B;" FontSize="13"/>
                </Button>


            </StackPanel>
        </Border>

        <!-- Row 3: Editor / Markdown preview -->
        <Grid x:Name="EditorGrid" Grid.Row="3">
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="*"/>
                <ColumnDefinition x:Name="SplitColumn" Width="0"/>
            </Grid.ColumnDefinitions>

            <RichEditBox x:Name="Editor"
                         Grid.Column="0"
                         AcceptsReturn="True"
                         TextWrapping="Wrap"
                         FontSize="14"
                         Padding="16,12"
                         BorderThickness="0"
                         ScrollViewer.VerticalScrollBarVisibility="Auto"
                         TextChanged="Editor_TextChanged"
                         SelectionChanged="Editor_SelectionChanged">
                <RichEditBox.Resources>
                    <SolidColorBrush x:Key="TextControlBackground" Color="Transparent"/>
                    <SolidColorBrush x:Key="TextControlBackgroundPointerOver" Color="Transparent"/>
                    <SolidColorBrush x:Key="TextControlBackgroundFocused" Color="Transparent"/>
                    <SolidColorBrush x:Key="TextControlBorderBrush" Color="Transparent"/>
                    <SolidColorBrush x:Key="TextControlBorderBrushPointerOver" Color="Transparent"/>
                    <SolidColorBrush x:Key="TextControlBorderBrushFocused" Color="Transparent"/>
                </RichEditBox.Resources>
            </RichEditBox>

            <!-- Split view: markdown preview panel (right half) -->
            <Border x:Name="SplitPreviewPanel" Grid.Column="1"
                    Visibility="Collapsed"
                    BorderBrush="{ThemeResource DividerStrokeColorDefaultBrush}"
                    BorderThickness="1,0,0,0">
                <ScrollViewer Padding="16,12"
                              VerticalScrollBarVisibility="Auto">
                    <ctk:MarkdownTextBlock x:Name="SplitPreviewMarkdown"
                                           IsTextSelectionEnabled="True"
                                           UsePipeTables="True"
                                           UseTaskLists="True"
                                           UseAutoLinks="True"/>
                </ScrollViewer>
            </Border>

            <!-- Markdown rendered view (overlays editor when active) -->
            <ScrollViewer x:Name="PreviewScroll"
                          Grid.ColumnSpan="2"
                          Padding="16,12"
                          VerticalScrollBarVisibility="Auto"
                          Visibility="Collapsed">
                <ctk:MarkdownTextBlock x:Name="PreviewMarkdown"
                                       IsTextSelectionEnabled="True"
                                       UsePipeTables="True"
                                       UseTaskLists="True"
                                       UseAutoLinks="True"/>
            </ScrollViewer>
        </Grid>

        <!-- Row 4: Status bar -->
        <Border Grid.Row="4"
                BorderBrush="{ThemeResource DividerStrokeColorDefaultBrush}"
                BorderThickness="0,1,0,0"
                Padding="12,5">
            <Grid>
                <StackPanel Orientation="Horizontal" HorizontalAlignment="Left" Spacing="20">
                    <Button x:Name="AiButton"
                            Background="Transparent" BorderThickness="0"
                            Padding="6,2" CornerRadius="4"
                            Click="AiMenu_Click">
                        <FontIcon Glyph="&#xE99A;" FontSize="11"
                                  Foreground="{ThemeResource TextFillColorSecondaryBrush}"/>
                    </Button>
                    <TextBlock x:Name="LineColText" Text="Ln 1, Col 1"
                               FontSize="11"
                               Foreground="{ThemeResource TextFillColorSecondaryBrush}"/>
                    <TextBlock x:Name="CharCountText"
                               FontSize="11"
                               Foreground="{ThemeResource TextFillColorSecondaryBrush}"/>
                    <TextBlock x:Name="WordCountText"
                               FontSize="11"
                               Foreground="{ThemeResource TextFillColorSecondaryBrush}"/>
                    <TextBlock x:Name="RichTextLabel"
                               FontSize="11"
                               Foreground="{ThemeResource TextFillColorSecondaryBrush}"/>
                </StackPanel>
                <StackPanel Orientation="Horizontal" HorizontalAlignment="Right" Spacing="12">
                    <Button x:Name="MarkdownToggle"
                            Background="Transparent" BorderThickness="0"
                            Padding="6,2" CornerRadius="4"
                            Click="MarkdownToggle_Click">
                        <TextBlock x:Name="MarkdownToggleText" Text="Markdown"
                                   FontSize="11"
                                   Foreground="{ThemeResource AccentTextFillColorPrimaryBrush}"/>
                    </Button>
                    <TextBlock x:Name="ZoomText" Text="100%"
                               FontSize="11"
                               Foreground="{ThemeResource TextFillColorSecondaryBrush}"/>
                    <TextBlock Text="Windows (CRLF)"
                               FontSize="11"
                               Foreground="{ThemeResource TextFillColorSecondaryBrush}"/>
                    <TextBlock Text="UTF-8"
                               FontSize="11"
                               Foreground="{ThemeResource TextFillColorSecondaryBrush}"/>
                </StackPanel>
            </Grid>
        </Border>
    </Grid>
</Window>