LehrerApp/LehrerApp.Desktop/Views/Groups/ExamDialog.axaml

<Window xmlns="https://github.com/avaloniaui"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:vm="clr-namespace:LehrerApp.Desktop.ViewModels.Groups"
        x:Class="LehrerApp.Desktop.Views.Groups.ExamDialog"
        x:DataType="vm:ExamDialogViewModel"
        Title="{Binding DialogTitle}"
        Width="640" Height="680" MinWidth="560" MinHeight="420"
        CanResize="True" WindowStartupLocation="CenterOwner">

  <Grid RowDefinitions="*,Auto" Margin="24">
    <ScrollViewer Grid.Row="0">
      <StackPanel Spacing="14" Margin="0,0,12,0">
        <StackPanel Spacing="2">
          <TextBlock Text="{Binding DialogTitle}" FontSize="18" FontWeight="SemiBold"/>
          <TextBlock Text="{Binding SubjectDisplay}" FontSize="12" Opacity="0.6"/>
        </StackPanel>

        <StackPanel Spacing="4">
          <TextBlock Text="Titel *" FontSize="12" Opacity="0.7"/>
          <TextBox Text="{Binding Title}" PlaceholderText="z.B. 1. Klausur Kinetik"/>
        </StackPanel>

        <Grid ColumnDefinitions="*,12,*,12,*">
          <StackPanel Grid.Column="0" Spacing="4">
            <TextBlock Text="Datum *" FontSize="12" Opacity="0.7"/>
            <TextBox Text="{Binding DateText}" PlaceholderText="TT.MM.JJJJ"/>
          </StackPanel>
          <StackPanel Grid.Column="2" Spacing="4">
            <TextBlock Text="Klausurnummer" FontSize="12" Opacity="0.7"/>
            <NumericUpDown Value="{Binding ExamNumber}" Minimum="1" Maximum="20" FormatString="0"
                           ShowButtonSpinner="False"/>
          </StackPanel>
          <StackPanel Grid.Column="4" Spacing="4">
            <TextBlock Text="Rückgabedatum" FontSize="12" Opacity="0.7"/>
            <TextBox Text="{Binding ReturnedAtText}" PlaceholderText="TT.MM.JJJJ"/>
          </StackPanel>
        </Grid>

        <StackPanel Spacing="4">
          <TextBlock Text="Notizen" FontSize="12" Opacity="0.7"/>
          <TextBox Text="{Binding Notes}" AcceptsReturn="True" Height="56" TextWrapping="Wrap"/>
        </StackPanel>

        <Separator Margin="0,4"/>

        <Grid ColumnDefinitions="*,Auto">
          <TextBlock Grid.Column="0" Text="Aufgaben" FontSize="14" FontWeight="SemiBold" VerticalAlignment="Center"/>
          <Button Grid.Column="1" Content="＋ Aufgabe" Command="{Binding AddTaskCommand}"/>
        </Grid>

        <CheckBox Content="Gewichtung verwenden" IsChecked="{Binding UseWeighting}"/>

        <Grid ColumnDefinitions="*,Auto">
          <TextBlock Grid.Column="0" Text="{Binding TotalPointsDisplay}" FontSize="12" Opacity="0.7"
                     VerticalAlignment="Center"/>
          <TextBlock Grid.Column="1" Text="Achtung: noch keine Punkte vergeben" Foreground="Red" FontSize="12"
                     IsVisible="{Binding TotalPointsWarning}" VerticalAlignment="Center"/>
        </Grid>

        <ItemsControl ItemsSource="{Binding Tasks}">
          <ItemsControl.ItemTemplate>
            <DataTemplate x:DataType="vm:ExamTaskEditItem">
              <Border BorderBrush="{DynamicResource SystemControlForegroundBaseLowBrush}"
                      BorderThickness="1" CornerRadius="4" Padding="8" Margin="0,0,0,6">
                <StackPanel Spacing="6">
                  <Grid ColumnDefinitions="26,*,Auto,Auto,Auto,Auto,Auto">
                    <TextBlock Grid.Column="0" Text="{Binding Nr}" VerticalAlignment="Center" Opacity="0.6"/>
                    <TextBox Grid.Column="1" Text="{Binding Title}" PlaceholderText="Titel der Aufgabe" Margin="0,0,6,0"/>
                    <NumericUpDown Grid.Column="2" Value="{Binding MaxPoints}" Minimum="0" FormatString="0.##"
                                   Width="72" ShowButtonSpinner="False" Margin="0,0,6,0" ToolTip.Tip="Maximalpunkte"/>
                    <NumericUpDown Grid.Column="3" Value="{Binding Weight}" Minimum="0" FormatString="0.##"
                                   Width="72" ShowButtonSpinner="False" Margin="0,0,6,0" ToolTip.Tip="Gewichtung"
                                   IsVisible="{Binding ShowWeight}"/>
                    <Button Grid.Column="4" Content="↑" Command="{Binding MoveUpCommand}" Padding="6,2"
                            ToolTip.Tip="Nach oben"/>
                    <Button Grid.Column="5" Content="↓" Command="{Binding MoveDownCommand}" Padding="6,2"
                            ToolTip.Tip="Nach unten" Margin="4,0,0,0"/>
                    <Button Grid.Column="6" Content="✕" Command="{Binding RemoveCommand}" Padding="6,2"
                            ToolTip.Tip="Entfernen" Margin="4,0,0,0"/>
                  </Grid>

                  <Button Content="{Binding CompetencySummary}" Command="{Binding ToggleCompetencyPanelCommand}"
                          HorizontalAlignment="Left" FontSize="11" Padding="6,2"/>

                  <ItemsControl ItemsSource="{Binding CompetencyTagGroups}" IsVisible="{Binding IsCompetencyPanelOpen}">
                    <ItemsControl.ItemTemplate>
                      <DataTemplate x:DataType="vm:CompetencyTagGroup">
                        <StackPanel Margin="12,2">
                          <TextBlock Text="{Binding DisplayName}" FontSize="11" Opacity="0.6"/>
                          <ItemsControl ItemsSource="{Binding Items}">
                            <ItemsControl.ItemsPanel>
                              <ItemsPanelTemplate>
                                <WrapPanel/>
                              </ItemsPanelTemplate>
                            </ItemsControl.ItemsPanel>
                            <ItemsControl.ItemTemplate>
                              <DataTemplate x:DataType="vm:CompetencyTag">
                                <ToggleButton Content="{Binding Display}" IsChecked="{Binding IsSelected}"
                                              Margin="0,2,6,2" FontSize="11" Padding="6,2"/>
                              </DataTemplate>
                            </ItemsControl.ItemTemplate>
                          </ItemsControl>
                        </StackPanel>
                      </DataTemplate>
                    </ItemsControl.ItemTemplate>
                  </ItemsControl>
                </StackPanel>
              </Border>
            </DataTemplate>
          </ItemsControl.ItemTemplate>
        </ItemsControl>

        <TextBlock Text="{Binding ValidationMessage}" Foreground="Red" FontSize="12"
                   IsVisible="{Binding ValidationMessage, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
      </StackPanel>
    </ScrollViewer>

    <Grid Grid.Row="1" ColumnDefinitions="*,8,*" Margin="0,20,0,0">
      <Button Grid.Column="0" Content="Abbrechen" HorizontalAlignment="Stretch" Click="OnCancel"/>
      <Button Grid.Column="2" Content="{Binding SaveButtonText}"
              HorizontalAlignment="Stretch" Click="OnSave"/>
    </Grid>
  </Grid>
</Window>