MainWindow.xaml

<Window x:Class="sqlSense.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:sqlSense"
        xmlns:models="clr-namespace:sqlSense.Models"
        xmlns:converters="clr-namespace:sqlSense.Converters"
        xmlns:ui="clr-namespace:sqlSense.UI"
        mc:Ignorable="d"
        Title="{Binding ActiveWorkbook.ViewName, StringFormat='sqlSense - {0}', TargetNullValue='sqlSense'}"
        Background="{StaticResource BackgroundBrush}"
        WindowStyle="SingleBorderWindow">
    
    <Window.Style>
        <Style TargetType="Window">
            <Style.Triggers>
                <DataTrigger Binding="{Binding HasUnsavedChanges}" Value="True">
                    <Setter Property="Title" Value="{Binding ActiveWorkbook.ViewName, StringFormat='sqlSense - {0} *'}"/>
                </DataTrigger>
            </Style.Triggers>
        </Style>
    </Window.Style>

    

    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="40"/>
            <RowDefinition Height="*"/>
            <RowDefinition Height="24"/>
        </Grid.RowDefinitions>

        <!-- Top Menu Bar -->
        <ui:TopMenuBar Grid.Row="0" />

        <!-- Main Content Area -->
        <Grid Grid.Row="1">
            <Grid.ColumnDefinitions>
                <ColumnDefinition>
                    <ColumnDefinition.Style>
                        <Style TargetType="ColumnDefinition">
                            <Setter Property="Width" Value="280"/>
                            <Setter Property="MinWidth" Value="180"/>
                            <Setter Property="MaxWidth" Value="450"/>
                            <Style.Triggers>
                                <DataTrigger Binding="{Binding SqlEditor.IsMaximized}" Value="True">
                                    <Setter Property="Width" Value="0"/>
                                    <Setter Property="MinWidth" Value="0"/>
                                </DataTrigger>
                            </Style.Triggers>
                        </Style>
                    </ColumnDefinition.Style>
                </ColumnDefinition>
                <ColumnDefinition>
                    <ColumnDefinition.Style>
                        <Style TargetType="ColumnDefinition">
                            <Setter Property="Width" Value="*"/>
                            <Style.Triggers>
                                <DataTrigger Binding="{Binding SqlEditor.IsMaximized}" Value="True">
                                    <Setter Property="Width" Value="0"/>
                                </DataTrigger>
                            </Style.Triggers>
                        </Style>
                    </ColumnDefinition.Style>
                </ColumnDefinition>
                <ColumnDefinition>
                    <ColumnDefinition.Style>
                        <Style TargetType="ColumnDefinition">
                            <Setter Property="Width" Value="300"/>
                            <Setter Property="MinWidth" Value="200"/>
                            <Setter Property="MaxWidth" Value="500"/>
                            <Style.Triggers>
                                <DataTrigger Binding="{Binding SqlEditor.IsMaximized}" Value="True">
                                    <Setter Property="Width" Value="*"/>
                                    <Setter Property="MaxWidth" Value="Infinity"/>
                                    <Setter Property="MinWidth" Value="200"/>
                                </DataTrigger>
                                <DataTrigger Binding="{Binding SqlEditor.IsVisible}" Value="False">
                                    <Setter Property="Width" Value="0"/>
                                    <Setter Property="MinWidth" Value="0"/>
                                </DataTrigger>
                            </Style.Triggers>
                        </Style>
                    </ColumnDefinition.Style>
                </ColumnDefinition>
            </Grid.ColumnDefinitions>

            <!-- LEFT PANEL: Object Explorer -->
            <ui:ObjectExplorerPanel x:Name="ObjectExplorerPanel" Grid.Column="0" 
                                    ItemExpanded="TreeViewItem_Expanded"
                                    SelectedItemChanged="ObjectExplorer_SelectedItemChanged" />

            <!-- CENTER PANEL: Infinite Canvas -->
            <Grid Grid.Column="1">
                <Grid.RowDefinitions>
                    <RowDefinition Height="35"/>
                    <RowDefinition Height="*"/>
                </Grid.RowDefinitions>

                <!-- Workbook Tabs (VS Code style) -->
                <ListBox Grid.Row="0" 
                         ItemsSource="{Binding OpenWorkbooks}"
                         SelectedItem="{Binding ActiveWorkbook}"
                         Background="#1E1E1E" 
                         BorderThickness="0,0,0,1"
                         BorderBrush="#252526"
                         ScrollViewer.HorizontalScrollBarVisibility="Auto"
                         ScrollViewer.VerticalScrollBarVisibility="Disabled">
                    <ListBox.ItemsPanel>
                        <ItemsPanelTemplate>
                            <StackPanel Orientation="Horizontal"/>
                        </ItemsPanelTemplate>
                    </ListBox.ItemsPanel>
                    <ListBox.ItemContainerStyle>
                        <Style TargetType="ListBoxItem">
                            <Setter Property="Background" Value="#2D2D2D"/>
                            <Setter Property="Padding" Value="0"/>
                            <Setter Property="BorderThickness" Value="0,0,1,0"/>
                            <Setter Property="BorderBrush" Value="#252526"/>
                            <Setter Property="Template">
                                <Setter.Value>
                                    <ControlTemplate TargetType="ListBoxItem">
                                        <Border x:Name="bd" Background="{TemplateBinding Background}" 
                                                BorderBrush="{TemplateBinding BorderBrush}" 
                                                BorderThickness="{TemplateBinding BorderThickness}"
                                                MinWidth="120" MaxWidth="200">
                                            <Grid Margin="12,0,8,0" Height="35">
                                                <Grid.ColumnDefinitions>
                                                    <ColumnDefinition Width="*"/>
                                                    <ColumnDefinition Width="Auto"/>
                                                </Grid.ColumnDefinitions>
                                                
                                                <StackPanel Orientation="Horizontal">
                                                    <TextBlock Text="&#xE8B3;" FontFamily="Segoe MDL2 Assets" 
                                                               FontSize="10" VerticalAlignment="Center" Margin="0,0,8,0"
                                                               Foreground="{StaticResource PrimaryAccentBrush}"/>
                                                    <TextBlock Text="{Binding ViewName}" 
                                                               Foreground="{StaticResource TextSecondaryBrush}" 
                                                               FontSize="11" VerticalAlignment="Center"
                                                               TextTrimming="CharacterEllipsis"/>
                                                </StackPanel>

                                                <Button Grid.Column="1"
                                                        x:Name="closeBtn"
                                                        Background="Transparent"
                                                        BorderThickness="0"
                                                        VerticalAlignment="Center"
                                                        Margin="8,0,0,0"
                                                        Cursor="Hand"
                                                        ToolTip="Close"
                                                        Command="{Binding DataContext.CloseWorkbookCommand, RelativeSource={RelativeSource AncestorType=Window}}"
                                                        CommandParameter="{Binding}">
                                                    <Control Template="{StaticResource CloseIcon}" Width="10" Height="10"
                                                             Foreground="{StaticResource MutedBrush}"/>
                                                </Button>
                                            </Grid>
                                        </Border>
                                        <ControlTemplate.Triggers>
                                            <Trigger Property="IsSelected" Value="True">
                                                <Setter Property="Background" Value="#1E1E1E"/>
                                                <Setter TargetName="bd" Property="BorderThickness" Value="0,2,1,0"/>
                                                <Setter TargetName="bd" Property="BorderBrush" Value="{StaticResource PrimaryAccentBrush}"/>
                                            </Trigger>
                                        </ControlTemplate.Triggers>
                                    </ControlTemplate>
                                </Setter.Value>
                            </Setter>
                        </Style>
                    </ListBox.ItemContainerStyle>
                </ListBox>

                <ui:InfiniteCanvasPanel x:Name="CanvasPanel" Grid.Row="1" />
            </Grid>

            <!-- RIGHT PANEL: SQL Editor -->
            <ui:SqlEditorPanel Grid.Column="2" />

            <!-- Resizers -->
            <GridSplitter Grid.Column="0" Width="4" Background="Transparent" HorizontalAlignment="Right" VerticalAlignment="Stretch">
                <GridSplitter.Style>
                    <Style TargetType="GridSplitter">
                        <Setter Property="Visibility" Value="Visible"/>
                        <Style.Triggers>
                            <DataTrigger Binding="{Binding SqlEditor.IsMaximized}" Value="True">
                                <Setter Property="Visibility" Value="Collapsed"/>
                            </DataTrigger>
                        </Style.Triggers>
                    </Style>
                </GridSplitter.Style>
            </GridSplitter>
            
            <GridSplitter Grid.Column="1" Width="4" Background="Transparent" HorizontalAlignment="Right" VerticalAlignment="Stretch">
                <GridSplitter.Style>
                    <Style TargetType="GridSplitter">
                        <Setter Property="Visibility" Value="Visible"/>
                        <Style.Triggers>
                            <DataTrigger Binding="{Binding SqlEditor.IsMaximized}" Value="True">
                                <Setter Property="Visibility" Value="Collapsed"/>
                            </DataTrigger>
                            <DataTrigger Binding="{Binding SqlEditor.IsVisible}" Value="False">
                                <Setter Property="Visibility" Value="Collapsed"/>
                            </DataTrigger>
                        </Style.Triggers>
                    </Style>
                </GridSplitter.Style>
            </GridSplitter>
        </Grid>

        <!-- Bottom Status Bar -->
        <Border Grid.Row="2" Background="{Binding StatusBackground}" BorderBrush="{StaticResource BorderBrush}" BorderThickness="0,1,0,0">
            <Grid Margin="10,0">
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="Auto"/>
                    <ColumnDefinition Width="*"/>
                    <ColumnDefinition Width="Auto"/>
                </Grid.ColumnDefinitions>

                <StackPanel Grid.Column="0" Orientation="Horizontal">
                    <TextBlock Text="&#xE99A;" FontFamily="Segoe MDL2 Assets" FontSize="11" Foreground="White" VerticalAlignment="Center" Margin="0,0,6,0"/>
                    <TextBlock Text="{Binding ServerName}" Foreground="White" FontSize="11" VerticalAlignment="Center" FontWeight="SemiBold"/>
                    <TextBlock Text=" | Connected" Foreground="#E0E0E0" FontSize="10" VerticalAlignment="Center" Margin="8,0,0,0"/>
                </StackPanel>

                <StackPanel Grid.Column="2" Orientation="Horizontal">
                    <Separator Width="1" Background="#40FFFFFF" Margin="10,4"/>
                    <TextBlock Text="{Binding StatusMessage}" Foreground="White" FontSize="11" VerticalAlignment="Center" Margin="5,0"/>
                </StackPanel>
            </Grid>
        </Border>

    </Grid>
</Window>