LehrerApp/LehrerApp.Desktop/Views/Students/StudentDetailView.axaml

<UserControl xmlns="https://github.com/avaloniaui"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:vm="clr-namespace:LehrerApp.Desktop.ViewModels.Students"
             x:Class="LehrerApp.Desktop.Views.Students.StudentDetailView"
             x:DataType="vm:StudentDetailViewModel">
  <Grid RowDefinitions="Auto,*">

    <!-- Header -->
    <Border Grid.Row="0" Padding="20,16"
            BorderBrush="{DynamicResource SystemControlForegroundBaseLowBrush}"
            BorderThickness="0,0,0,1">
      <Grid ColumnDefinitions="*,Auto">
        <StackPanel Grid.Column="0"  IsVisible="{Binding !IsEditing}">
          <TextBlock Text="{Binding StudentTitle}" FontSize="22" FontWeight="SemiBold"/>
        </StackPanel>
        <StackPanel Grid.Column="0" Spacing="6" IsVisible="{Binding IsEditing}">
          <Grid ColumnDefinitions="*,8,*">
            <TextBox Grid.Column="0" Text="{Binding EditFirstName}" PlaceholderText="Vorname"/>
            <TextBox Grid.Column="2" Text="{Binding EditLastName}"  PlaceholderText="Nachname"/>
          </Grid>
        </StackPanel>
        <StackPanel Grid.Column="1" Orientation="Horizontal" Spacing="8" VerticalAlignment="Top">
          <Button Content="Bearbeiten" Command="{Binding StartEditCommand}"
                  IsVisible="{Binding !IsEditing}"/>
          <Button Content="Speichern"  Command="{Binding SaveEditCommand}"
                  IsVisible="{Binding IsEditing}"/>
          <Button Content="Abbrechen"  Command="{Binding CancelEditCommand}"
                  IsVisible="{Binding IsEditing}"/>
        </StackPanel>
      </Grid>
    </Border>

    <!--
      Avalonia 12: TabbedPage für Schüler-Tabs.
      Kein manuelles Tab-Management nötig.
    -->
    <TabbedPage Grid.Row="1" TabPlacement="Top">

      <ContentPage Header="Übersicht">
        <ScrollViewer Padding="20">
          <StackPanel Spacing="12">
            <TextBlock Text="Lerngruppen" FontSize="15" FontWeight="SemiBold"/>
            <ItemsControl ItemsSource="{Binding Enrollments}">
              <ItemsControl.ItemTemplate>
                <DataTemplate DataType="vm:EnrollmentEntry">
                  <Border Background="{DynamicResource SystemControlBackgroundAltHighBrush}"
                          CornerRadius="6" Padding="12,8" Margin="0,0,0,6">
                    <Grid ColumnDefinitions="70,*,Auto">
                      <TextBlock Grid.Column="0" Text="{Binding SchoolYear}" FontWeight="SemiBold"/>
                      <TextBlock Grid.Column="1" Text="{Binding GroupName}" Margin="8,0"/>
                      <TextBlock Grid.Column="2" Text="{Binding Subject}" Opacity="0.5" FontSize="12"/>
                    </Grid>
                  </Border>
                </DataTemplate>
              </ItemsControl.ItemTemplate>
            </ItemsControl>
            <TextBlock Text="Keine Einschreibungen vorhanden." Opacity="0.4"
                       IsVisible="{Binding !Enrollments.Count}"/>
          </StackPanel>
        </ScrollViewer>
      </ContentPage>

      <ContentPage Header="Kontakte">
        <Grid RowDefinitions="Auto,*" Margin="20">
          <Grid Grid.Row="0" ColumnDefinitions="*,Auto,Auto,Auto" Margin="0,0,0,10">
            <TextBlock Grid.Column="0" Text="Kontaktdaten" FontSize="15"
                       FontWeight="SemiBold" VerticalAlignment="Center"/>
            <Button Grid.Column="1" Content="＋ Neu" Command="{Binding AddContactCommand}"
                    Margin="0,0,8,0"/>
            <Button Grid.Column="2" Content="Bearbeiten" Command="{Binding EditContactCommand}"
                    Margin="0,0,8,0"/>
            <Button Grid.Column="3" Content="Adresse anzeigen"
                    Command="{Binding ViewSelectedAddressCommand}"/>
          </Grid>

          <ListBox Grid.Row="1" x:Name="ContactList"
                   ItemsSource="{Binding Contacts}"
                   SelectedItem="{Binding SelectedContact}"
                   DoubleTapped="OnContactDoubleTapped">
            <ListBox.ItemTemplate>
                <DataTemplate x:DataType="vm:ContactItem">
                  <Border Background="{DynamicResource SystemControlBackgroundAltHighBrush}"
                          CornerRadius="8" Padding="14,10" Margin="2,3">
                    <Grid ColumnDefinitions="220,*,Auto" RowDefinitions="Auto,Auto">
                      <StackPanel Grid.Column="0" Grid.RowSpan="2" Spacing="4">
                        <TextBlock Text="{Binding Name}" FontWeight="SemiBold" FontSize="14"
                                   TextWrapping="Wrap"/>
                        <Border Background="{DynamicResource SystemControlForegroundBaseLowBrush}"
                                CornerRadius="4" Padding="6,2" HorizontalAlignment="Left">
                          <TextBlock Text="{Binding Relation}" FontSize="11" Opacity="0.7"/>
                        </Border>
                      </StackPanel>

                      <StackPanel Grid.Column="1" Grid.Row="0" Orientation="Horizontal" Spacing="8">
                        <Button Content="{Binding PhoneDisplay}"
                                Command="{Binding CallCommand}"
                                IsVisible="{Binding HasPhone}"
                                FontSize="12" Padding="8,4"/>
                        <Button Content="{Binding EmailDisplay}"
                                Command="{Binding MailCommand}"
                                IsVisible="{Binding HasEmail}"
                                FontSize="12" Padding="8,4"/>
                      </StackPanel>

                      <TextBlock Grid.Column="1" Grid.Row="1" Text="{Binding Address}"
                                 IsVisible="{Binding HasAddress}" FontSize="12" Opacity="0.65"
                                 TextWrapping="Wrap" Margin="4,4,12,0"/>

                      <Border Grid.Column="2" Grid.RowSpan="2" CornerRadius="4" Padding="7,3"
                              VerticalAlignment="Top"
                              Background="{DynamicResource SystemControlBackgroundAltHighBrush}">
                        <StackPanel>
                          <TextBlock Text="{Binding StatusText}" FontSize="11"
                                     IsVisible="{Binding IsInvalid}" Foreground="IndianRed"/>
                          <TextBlock Text="Aktuell" FontSize="11" Opacity="0.5"
                                     IsVisible="{Binding IsValid}"/>
                        </StackPanel>
                      </Border>
                    </Grid>
                  </Border>
                </DataTemplate>
            </ListBox.ItemTemplate>
          </ListBox>

            <TextBlock Text="Keine Kontakte erfasst." Opacity="0.4"
                       HorizontalAlignment="Center" VerticalAlignment="Center"
                       IsVisible="{Binding HasNoContacts}"/>
        </Grid>
      </ContentPage>

      <ContentPage Header="Noten">
        <StackPanel HorizontalAlignment="Center" VerticalAlignment="Center">
          <TextBlock Text="Notenübersicht" FontSize="16" Opacity="0.4" HorizontalAlignment="Center"/>
          <TextBlock Text="Wird implementiert." FontSize="12" Opacity="0.3" HorizontalAlignment="Center"/>
        </StackPanel>
      </ContentPage>

      <ContentPage Header="Dokumentation">
        <ScrollViewer Padding="20">
          <StackPanel>
            <ItemsControl ItemsSource="{Binding Documentation}">
              <ItemsControl.ItemTemplate>
                <DataTemplate DataType="vm:DocEntry">
                  <Border Background="{DynamicResource SystemControlBackgroundAltHighBrush}"
                          CornerRadius="6" Padding="12,10" Margin="0,0,0,8">
                    <Grid ColumnDefinitions="80,*,Auto">
                      <TextBlock Grid.Column="0" Text="{Binding Date}" Opacity="0.5" FontSize="12"/>
                      <StackPanel Grid.Column="1" Margin="8,0">
                        <TextBlock Text="{Binding Title}" FontWeight="SemiBold" FontSize="13"/>
                        <TextBlock Text="{Binding TypeLabel}" FontSize="11" Opacity="0.5"/>
                      </StackPanel>
                      <TextBlock Grid.Column="2" Text="🔒" FontSize="14"
                                 IsVisible="{Binding IsConfidential}"
                                 ToolTip.Tip="Vertraulich"/>
                    </Grid>
                  </Border>
                </DataTemplate>
              </ItemsControl.ItemTemplate>
            </ItemsControl>
            <TextBlock Text="Keine Dokumentation vorhanden." Opacity="0.4"
                       IsVisible="{Binding !Documentation.Count}"/>
          </StackPanel>
        </ScrollViewer>
      </ContentPage>

    </TabbedPage>
  </Grid>
</UserControl>