LANCommander/LANCommander.Launcher/Views/InstallOptionsWindow.axaml

<Window xmlns="https://github.com/avaloniaui"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:vm="using:LANCommander.Launcher.ViewModels"
        x:Class="LANCommander.Launcher.Views.InstallOptionsWindow"
        x:DataType="vm:InstallOptionsViewModel"
        Title="Install Options"
        Width="460"
        SizeToContent="Height"
        MinHeight="160"
        MaxHeight="600"
        WindowStartupLocation="CenterOwner"
        CanResize="False">

    <Window.Styles>
        <Style Selector="ToggleButton.AddonItem">
            <Setter Property="Background" Value="{DynamicResource SystemControlBackgroundChromeMediumLowBrush}" />
            <Setter Property="Padding" Value="10,8" />
            <Setter Property="HorizontalAlignment" Value="Stretch" />
            <Setter Property="HorizontalContentAlignment" Value="Stretch" />
            <Setter Property="BorderThickness" Value="0" />
            <Setter Property="CornerRadius" Value="6" />
        </Style>
        <Style Selector="ToggleButton.AddonItem:checked">
            <Setter Property="Background" Value="{DynamicResource SystemControlBackgroundChromeMediumBrush}" />
        </Style>
    </Window.Styles>

    <StackPanel Spacing="0">

        <!-- ── Header ───────────────────────────────────────────────────── -->
        <Border Padding="20,16,20,0">
            <TextBlock FontSize="18" FontWeight="Bold"
                       HorizontalAlignment="Center"
                       TextTrimming="CharacterEllipsis">
                <Run Text="Install " /><Run Text="{Binding GameTitle}" />
            </TextBlock>
        </Border>

        <!-- ── Size info ────────────────────────────────────────────────── -->
        <Border IsVisible="{Binding HasAddons}"
                Padding="20,24,20,8">
            <UniformGrid Columns="2">
                <StackPanel HorizontalAlignment="Center">
                    <TextBlock Text="Download Size"
                               FontSize="11" Opacity="0.55"
                               HorizontalAlignment="Center" />
                    <TextBlock Text="{Binding DownloadSizeText}"
                               FontSize="18" FontWeight="SemiBold"
                               HorizontalAlignment="Center" />
                </StackPanel>
                <StackPanel HorizontalAlignment="Center">
                    <TextBlock Text="Space Required"
                               FontSize="11" Opacity="0.55"
                               HorizontalAlignment="Center" />
                    <TextBlock Text="{Binding SpaceRequiredText}"
                               FontSize="18" FontWeight="SemiBold"
                               HorizontalAlignment="Center" />
                </StackPanel>
            </UniformGrid>
        </Border>

        <!-- ── Addons ───────────────────────────────────────────────────── -->
        <Border IsVisible="{Binding HasAddons}"
                Padding="20,16,20,0">
            <StackPanel Spacing="8">
                <DockPanel>
                    <Button DockPanel.Dock="Right"
                            Content="None"
                            Background="Transparent"
                            Padding="8,2"
                            FontSize="12"
                            Click="DeselectAllAddons_Click" />
                    <Button DockPanel.Dock="Right"
                            Content="All"
                            Background="Transparent"
                            Padding="8,2"
                            FontSize="12"
                            Margin="0,0,4,0"
                            Click="SelectAllAddons_Click" />
                    <TextBlock Text="Optional Add-ons"
                               FontSize="13" FontWeight="SemiBold"
                               VerticalAlignment="Center" />
                </DockPanel>

                <ScrollViewer MaxHeight="280"
                              HorizontalScrollBarVisibility="Disabled"
                              VerticalScrollBarVisibility="Auto">
                    <ItemsControl ItemsSource="{Binding Addons}">
                        <ItemsControl.ItemTemplate>
                            <DataTemplate DataType="vm:InstallAddonItemViewModel">
                                <ToggleButton Classes="AddonItem"
                                              IsChecked="{Binding IsSelected}"
                                              Margin="0,0,0,3">
                                    <DockPanel>
                                        <Icon DockPanel.Dock="Left"
                                              Type="Regular" Value="Check"
                                              Width="12" Height="12"
                                              IsVisible="{Binding IsSelected}"
                                              Margin="0,0,10,0"
                                              VerticalAlignment="Center" />
                                        <TextBlock DockPanel.Dock="Right"
                                                   Text="{Binding TypeLabel}"
                                                   FontSize="11"
                                                   Opacity="0.55"
                                                   VerticalAlignment="Center" />
                                        <TextBlock Text="{Binding Title}"
                                                   FontSize="13"
                                                   VerticalAlignment="Center"
                                                   TextTrimming="CharacterEllipsis" />
                                    </DockPanel>
                                </ToggleButton>
                            </DataTemplate>
                        </ItemsControl.ItemTemplate>
                    </ItemsControl>
                </ScrollViewer>
            </StackPanel>
        </Border>

        <!-- ── Install directory ────────────────────────────────────────── -->
        <Border IsVisible="{Binding HasMultipleDirectories}"
                Padding="20,16,20,0">
            <StackPanel Spacing="8">
                <TextBlock Text="Install Location"
                           FontSize="13" FontWeight="SemiBold" />
                <ComboBox ItemsSource="{Binding InstallDirectories}"
                          SelectedItem="{Binding SelectedInstallDirectory}"
                          HorizontalAlignment="Stretch" />
            </StackPanel>
        </Border>

        <!-- ── Buttons ──────────────────────────────────────────────────── -->
        <Border Padding="20,16">
            <StackPanel Orientation="Horizontal"
                        HorizontalAlignment="Right"
                        Spacing="8"
                        Classes="DialogFooter">
                <Button Content="Cancel"
                        Click="Cancel_Click" />
                <Button Content="Install"
                        Classes="Primary"
                        Click="Confirm_Click" />
            </StackPanel>
        </Border>

    </StackPanel>
</Window>