MainWindow.xaml

<Window
    x:Class="MiniT.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MiniT">

    <Grid x:Name="RootGrid" RowDefinitions="44,Auto,*">

        <!-- ================= CUSTOM TITLE BAR (draggable) ================= -->
        <Grid x:Name="AppTitleBar" Grid.Row="0"
              Background="Transparent"/>

        <!-- ================= SEARCH BAR ================= -->
        <Grid Grid.Row="1" Padding="16,4,16,12" HorizontalAlignment="Stretch">
            <Button x:Name="SearchBarButton"
                    HorizontalAlignment="Stretch"
                    Click="OnSearchClick"
                    Background="{ThemeResource CardBackgroundFillColorDefaultBrush}"
                    BorderBrush="{ThemeResource CardStrokeColorDefaultBrush}"
                    BorderThickness="1" CornerRadius="10" Padding="14,0" Height="38">
                <Grid ColumnDefinitions="Auto,*,Auto">
                    <FontIcon Grid.Column="0" Glyph="&#xE721;" FontSize="13"
                              Foreground="{ThemeResource TextFillColorSecondaryBrush}"/>
                    <TextBlock Grid.Column="1" Text="Search tools…"
                               Foreground="{ThemeResource TextFillColorSecondaryBrush}"
                               VerticalAlignment="Center" FontSize="13.5" Margin="10,0,0,0"/>
                    <Border Grid.Column="2" Background="{ThemeResource SubtleFillColorSecondaryBrush}"
                            CornerRadius="5" Padding="7,3">
                        <TextBlock Text="Ctrl+K"
                                   Foreground="{ThemeResource TextFillColorTertiaryBrush}"
                                   FontSize="11" FontWeight="SemiBold"/>
                    </Border>
                </Grid>
            </Button>
        </Grid>

        <!-- ================= MAIN: SIDEBAR + CONTENT ================= -->
        <Grid Grid.Row="2">
            <Grid.ColumnDefinitions>
                <ColumnDefinition x:Name="SidebarColumn" Width="248"/>
                <ColumnDefinition Width="6"/>
                <ColumnDefinition Width="*"/>
            </Grid.ColumnDefinitions>

            <!-- SIDEBAR -->
            <Grid Grid.Column="0" RowDefinitions="*,Auto"
                  Background="{ThemeResource LayerFillColorDefaultBrush}"
                  BorderBrush="{ThemeResource CardStrokeColorDefaultBrush}"
                  BorderThickness="0,1,1,0">

                <ScrollViewer Grid.Row="0" Padding="0,10">
                    <StackPanel>
                        <TextBlock x:Name="SpacesHeaderLabel" Text="SPACES" Style="{StaticResource EyebrowTextStyle}"
                                   Margin="18,6,16,8"/>
                        <ItemsRepeater x:Name="SpaceList">
                            <ItemsRepeater.Layout>
                                <StackLayout Spacing="2"/>
                            </ItemsRepeater.Layout>
                        </ItemsRepeater>
                    </StackPanel>
                </ScrollViewer>

                <StackPanel Grid.Row="1" x:Name="SidebarFooter" Margin="10,8,10,12" Spacing="4">
                    <Border BorderThickness="0,1,0,0"
                            BorderBrush="{ThemeResource CardStrokeColorDefaultBrush}"
                            Margin="4,0,4,8"/>
                    <Button x:Name="AddSpaceButton" Click="OnAddSpace" Style="{StaticResource SidebarNavButtonStyle}"
                            ToolTipService.ToolTip="New Space">
                        <StackPanel Orientation="Horizontal" Spacing="10">
                            <FontIcon Glyph="&#xE710;" FontSize="14"
                                      Foreground="{ThemeResource TextFillColorSecondaryBrush}"/>
                            <TextBlock x:Name="AddSpaceLabel" Text="New Space"/>
                        </StackPanel>
                    </Button>
                    <Button x:Name="AddToolButton" Click="OnAddTool" Style="{StaticResource SidebarNavButtonStyle}"
                            ToolTipService.ToolTip="Add Tool">
                        <StackPanel Orientation="Horizontal" Spacing="10">
                            <FontIcon Glyph="&#xE71B;" FontSize="14"
                                      Foreground="{ThemeResource TextFillColorSecondaryBrush}"/>
                            <TextBlock x:Name="AddToolLabel" Text="Add Tool"/>
                        </StackPanel>
                    </Button>
                    <Button x:Name="SettingsButton" Click="OnSettings" Style="{StaticResource SidebarNavButtonStyle}"
                            ToolTipService.ToolTip="Settings">
                        <StackPanel Orientation="Horizontal" Spacing="10">
                            <FontIcon Glyph="&#xE713;" FontSize="14"
                                      Foreground="{ThemeResource TextFillColorSecondaryBrush}"/>
                            <TextBlock x:Name="SettingsLabel" Text="Settings"/>
                        </StackPanel>
                    </Button>
                    <Button x:Name="CollapseSidebarButton" Click="OnToggleSidebarCollapsed" Style="{StaticResource SidebarNavButtonStyle}"
                            ToolTipService.ToolTip="Collapse sidebar">
                        <StackPanel Orientation="Horizontal" Spacing="10">
                            <FontIcon x:Name="CollapseIcon" Glyph="&#xE76B;" FontSize="14"
                                      Foreground="{ThemeResource TextFillColorSecondaryBrush}"/>
                            <TextBlock x:Name="CollapseLabel" Text="Collapse"/>
                        </StackPanel>
                    </Button>
                </StackPanel>
            </Grid>

            <!-- SPLITTER — drag to resize the sidebar -->
            <Border Grid.Column="1" x:Name="Splitter"
                    Background="Transparent"
                    PointerEntered="OnSplitterPointerEntered"
                    PointerExited="OnSplitterPointerExited"
                    PointerPressed="OnSplitterPointerPressed"
                    PointerMoved="OnSplitterPointerMoved"
                    PointerReleased="OnSplitterPointerReleased">
                <Border x:Name="SplitterLine" Width="1" HorizontalAlignment="Center"
                        Background="{ThemeResource CardStrokeColorDefaultBrush}"/>
            </Border>

            <!-- CONTENT -->
            <Grid Grid.Column="2" RowDefinitions="Auto,*"
                  Background="{ThemeResource SolidBackgroundFillColorBaseBrush}">
                <Border Grid.Row="0" x:Name="TabBarHost"
                        BorderBrush="{ThemeResource CardStrokeColorDefaultBrush}"
                        BorderThickness="0,0,0,1"
                        Visibility="Collapsed">
                    <ScrollViewer x:Name="TabBarScroller"
                                  HorizontalScrollMode="Auto"
                                  HorizontalScrollBarVisibility="Hidden"
                                  VerticalScrollMode="Disabled">
                        <StackPanel x:Name="TabBar" Orientation="Horizontal"
                                    Spacing="4" Padding="12,8,12,0"/>
                    </ScrollViewer>
                </Border>
                <Frame Grid.Row="1" x:Name="ContentFrame"/>
            </Grid>
        </Grid>

        <!-- ================= SEARCH OVERLAY (command palette) ================= -->
        <Grid x:Name="SearchOverlay" Grid.RowSpan="3"
              Visibility="Collapsed"
              Background="{ThemeResource SmokeFillColorDefaultBrush}"
              PointerPressed="OnSearchOverlayBackgroundPressed">
            <Border x:Name="SearchCard" MaxWidth="640" MaxHeight="520"
                    HorizontalAlignment="Center" VerticalAlignment="Top"
                    Margin="0,90,0,0" CornerRadius="16"
                    RenderTransformOrigin="0.5,0.5"
                    Background="{ThemeResource AcrylicInAppFillColorDefaultBrush}"
                    BorderBrush="{ThemeResource CardStrokeColorDefaultBrush}"
                    BorderThickness="1"
                    Translation="0,0,64"
                    Shadow="{StaticResource CardShadow}">
                <Border.RenderTransform>
                    <ScaleTransform x:Name="SearchCardScale" ScaleX="0.97" ScaleY="0.97"/>
                </Border.RenderTransform>
                <Grid RowDefinitions="Auto,Auto,*">
                    <Grid Grid.Row="0" ColumnDefinitions="Auto,*" Padding="18,14,18,10">
                        <FontIcon Grid.Column="0" Glyph="&#xE721;" FontSize="16"
                                  VerticalAlignment="Center"
                                  Foreground="{ThemeResource TextFillColorSecondaryBrush}"/>
                        <TextBox Grid.Column="1" x:Name="SearchBox"
                                 PlaceholderText="Search tools…"
                                 BorderThickness="0" Background="Transparent"
                                 Padding="10,4" FontSize="17"
                                 TextChanged="OnSearchTextChanged"
                                 KeyDown="OnSearchKeyDown"/>
                    </Grid>

                    <Border Grid.Row="1" BorderThickness="0,1,0,1"
                            BorderBrush="{ThemeResource CardStrokeColorDefaultBrush}"
                            Padding="14,8">
                        <Border Background="{ThemeResource SubtleFillColorSecondaryBrush}"
                                CornerRadius="10" Padding="2" HorizontalAlignment="Left">
                            <Grid x:Name="FilterButtonsPanel">
                                <!-- Sits behind the radio buttons and slides/resizes itself
                                     to sit exactly under whichever one is checked, instead of
                                     each pill just flipping its own background instantly. -->
                                <Border x:Name="FilterIndicator"
                                        Background="{StaticResource AppAccentBrush}"
                                        CornerRadius="8" Width="60"
                                        HorizontalAlignment="Left" VerticalAlignment="Stretch">
                                    <Border.RenderTransform>
                                        <TranslateTransform x:Name="FilterIndicatorTransform"/>
                                    </Border.RenderTransform>
                                </Border>
                                <StackPanel Orientation="Horizontal" Spacing="0">
                                    <RadioButton x:Name="FilterAll" Content="All"
                                                 Style="{StaticResource FilterPillRadioButtonStyle}"
                                                 IsChecked="True" GroupName="sf"
                                                 Checked="OnFilterChanged"/>
                                    <RadioButton x:Name="FilterLocal" Content="Local"
                                                 Style="{StaticResource FilterPillRadioButtonStyle}"
                                                 GroupName="sf" Checked="OnFilterChanged"/>
                                    <RadioButton x:Name="FilterOnline" Content="Online"
                                                 Style="{StaticResource FilterPillRadioButtonStyle}"
                                                 GroupName="sf" Checked="OnFilterChanged"/>
                                </StackPanel>
                            </Grid>
                        </Border>
                    </Border>

                    <ScrollViewer Grid.Row="2" MaxHeight="360">
                        <Border Padding="10,8,10,10">
                            <ItemsRepeater x:Name="SearchResultsList">
                                <ItemsRepeater.Layout>
                                    <StackLayout Spacing="2"/>
                                </ItemsRepeater.Layout>
                            </ItemsRepeater>
                        </Border>
                    </ScrollViewer>
                </Grid>
            </Border>
        </Grid>
    </Grid>
</Window>