LehrerApp/LehrerApp.Desktop/Views/Settings/SettingsView.axaml

<UserControl xmlns="https://github.com/avaloniaui"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:vm="clr-namespace:LehrerApp.Desktop.ViewModels.Settings"
             x:Class="LehrerApp.Desktop.Views.Settings.SettingsView"
             x:DataType="vm:SettingsViewModel">

  <ScrollViewer>
    <StackPanel Margin="32,28" Spacing="32" MaxWidth="640">

      <TextBlock Text="Einstellungen" FontSize="22" FontWeight="SemiBold"/>

      <!-- ── FÄCHER ────────────────────────────────────────────────── -->
      <StackPanel Spacing="10">
        <TextBlock Text="FÄCHER" FontSize="10" FontWeight="Bold" Opacity="0.4"/>

        <ItemsControl ItemsSource="{Binding Subjects}">
          <ItemsControl.ItemTemplate>
            <DataTemplate DataType="vm:SubjectListItem">
              <Border BorderBrush="{DynamicResource SystemControlForegroundBaseLowBrush}"
                      BorderThickness="0,0,0,1" Padding="0,7">
                <Grid ColumnDefinitions="*,80,Auto">
                  <TextBlock Grid.Column="0" Text="{Binding Name}"
                             VerticalAlignment="Center" FontSize="14"/>
                  <TextBlock Grid.Column="1" Text="{Binding ShortName}"
                             VerticalAlignment="Center" Opacity="0.5" FontSize="13"/>
                  <Button Grid.Column="2" Content="Löschen" FontSize="12" Padding="10,4"
                          Command="{Binding $parent[ItemsControl].((vm:SettingsViewModel)DataContext).DeleteSubjectCommand}"
                          CommandParameter="{Binding}"/>
                </Grid>
              </Border>
            </DataTemplate>
          </ItemsControl.ItemTemplate>
        </ItemsControl>

        <Border BorderBrush="{DynamicResource SystemControlForegroundBaseLowBrush}"
                BorderThickness="1" CornerRadius="6" Padding="14,12">
          <StackPanel Spacing="10">
            <TextBlock Text="Neues Fach" FontSize="12" FontWeight="SemiBold" Opacity="0.7"/>
            <Grid ColumnDefinitions="*,12,100,12,Auto">
              <TextBox Grid.Column="0" Text="{Binding NewName}"
                       PlaceholderText="Name  (z.B. Chemie)"/>
              <TextBox Grid.Column="2" Text="{Binding NewShort}"
                       PlaceholderText="Kürzel  (z.B. Ch)"/>
              <Button  Grid.Column="4" Content="Hinzufügen"
                       Command="{Binding AddSubjectCommand}"/>
            </Grid>
            <TextBlock Text="{Binding ValidationMessage}" Foreground="Red" FontSize="12"
                       IsVisible="{Binding ValidationMessage, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
          </StackPanel>
        </Border>
      </StackPanel>

      <!-- ── KOMPETENZKATALOGE ─────────────────────────────────────── -->
      <StackPanel Spacing="10">
        <TextBlock Text="KOMPETENZKATALOGE" FontSize="10" FontWeight="Bold" Opacity="0.4"/>

        <!-- Fach + Klassenstufe Auswahl + Import/Export -->
        <Grid ColumnDefinitions="*,12,120,12,Auto,8,Auto">
          <ComboBox Grid.Column="0"
                    ItemsSource="{Binding Subjects}"
                    SelectedItem="{Binding CatalogSubject}"
                    PlaceholderText="Fach auswählen"
                    HorizontalAlignment="Stretch">
            <ComboBox.ItemTemplate>
              <DataTemplate DataType="vm:SubjectListItem">
                <TextBlock Text="{Binding Name}"/>
              </DataTemplate>
            </ComboBox.ItemTemplate>
          </ComboBox>
          <NumericUpDown Grid.Column="2"
                         Value="{Binding CatalogGradeLevel}"
                         Minimum="1" Maximum="13" FormatString="0"/>
          <Button Grid.Column="4" Content="Import JSON" Click="OnImportClick"
                  IsEnabled="{Binding CatalogSubject, Converter={x:Static ObjectConverters.IsNotNull}}"/>
          <Button Grid.Column="6" Content="Export JSON" Click="OnExportClick"
                  IsEnabled="{Binding CatalogSubject, Converter={x:Static ObjectConverters.IsNotNull}}"/>
        </Grid>

        <!-- Katalog-Validierungsmeldung -->
        <TextBlock Text="{Binding CatalogValidation}" Foreground="Red" FontSize="12"
                   IsVisible="{Binding CatalogValidation, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>

        <!-- Leerer Zustand -->
        <TextBlock Text="Kein Fach ausgewählt." Opacity="0.4" FontSize="13"
                   IsVisible="{Binding CatalogSubject, Converter={x:Static ObjectConverters.IsNull}}"/>

        <!-- Domain-Liste -->
        <ItemsControl ItemsSource="{Binding Domains}"
                      IsVisible="{Binding CatalogSubject, Converter={x:Static ObjectConverters.IsNotNull}}">
          <ItemsControl.ItemTemplate>
            <DataTemplate DataType="vm:DomainEditItem">
              <Border BorderBrush="{DynamicResource SystemControlForegroundBaseLowBrush}"
                      BorderThickness="1" CornerRadius="6" Margin="0,0,0,8" Padding="14,12">
                <StackPanel Spacing="8">

                  <!-- Bereichs-Header -->
                  <Grid ColumnDefinitions="*,Auto">
                    <TextBlock Grid.Column="0" Text="{Binding DisplayName}"
                               FontWeight="SemiBold" FontSize="14" VerticalAlignment="Center"/>
                    <Button Grid.Column="1" Content="Bereich löschen" FontSize="12" Padding="10,4"
                            Command="{Binding $parent[ItemsControl].((vm:SettingsViewModel)DataContext).DeleteDomainCommand}"
                            CommandParameter="{Binding}"/>
                  </Grid>

                  <!-- Kompetenz-Items -->
                  <ItemsControl ItemsSource="{Binding Items}">
                    <ItemsControl.ItemTemplate>
                      <DataTemplate DataType="vm:CompetencyItemVm">
                        <Grid ColumnDefinitions="*,Auto" Margin="0,3">
                          <TextBlock Grid.Column="0" Text="{Binding Display}"
                                     TextWrapping="Wrap" VerticalAlignment="Center"
                                     FontSize="13"/>
                          <Button Grid.Column="1" Content="×" Padding="7,2" FontSize="13"
                                  Command="{Binding DeleteCommand}"/>
                        </Grid>
                      </DataTemplate>
                    </ItemsControl.ItemTemplate>
                  </ItemsControl>

                  <!-- Kompetenz hinzufügen -->
                  <Grid ColumnDefinitions="80,8,*,8,Auto">
                    <TextBox Grid.Column="0" Text="{Binding NewItemCode}"
                             PlaceholderText="EG1" FontSize="12"/>
                    <TextBox Grid.Column="2" Text="{Binding NewItemDesc}"
                             PlaceholderText="Kompetenz-Beschreibung" FontSize="12"/>
                    <Button  Grid.Column="4" Content="＋"
                             Command="{Binding AddItemCommand}"/>
                  </Grid>

                </StackPanel>
              </Border>
            </DataTemplate>
          </ItemsControl.ItemTemplate>
        </ItemsControl>

        <!-- Neuen Bereich hinzufügen -->
        <Border BorderBrush="{DynamicResource SystemControlForegroundBaseLowBrush}"
                BorderThickness="1" CornerRadius="6" Padding="14,12"
                IsVisible="{Binding CatalogSubject, Converter={x:Static ObjectConverters.IsNotNull}}">
          <StackPanel Spacing="10">
            <TextBlock Text="Neuer Bereich" FontSize="12" FontWeight="SemiBold" Opacity="0.7"/>
            <Grid ColumnDefinitions="*,12,90,12,Auto">
              <TextBox Grid.Column="0" Text="{Binding NewDomainName}"
                       PlaceholderText="Bereichsname  (z.B. Erkenntnisgewinnung)"/>
              <TextBox Grid.Column="2" Text="{Binding NewDomainCode}"
                       PlaceholderText="Kürzel  (z.B. EG)"/>
              <Button  Grid.Column="4" Content="Hinzufügen"
                       Command="{Binding AddDomainCommand}"/>
            </Grid>
          </StackPanel>
        </Border>

      </StackPanel>

    </StackPanel>
  </ScrollViewer>
</UserControl>