presence/Presence.Desktop/Views/GroupView.axaml

<Window xmlns="https://github.com/avaloniaui"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:vm="using:Presence.Desktop.ViewModels"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
        x:Class="Presence.Desktop.Views.MainWindow"
        Icon="/Assets/avalonia-logo.ico"
        Title="Presence.Desktop"
        x:DataType="vm:MainWindowViewModel"
        xmlns:local="clr-namespace:Presence.Desktop.ViewModels"
        DataContext="{Binding RelativeSource={RelativeSource Self}}">

    <Window.Styles>
        <!-- Общие стили -->
        <Style Selector="TextBlock">
            <Setter Property="Foreground" Value="#333333"/>
            <Setter Property="FontSize" Value="14"/>
            <Setter Property="FontWeight" Value="Medium"/>
        </Style>
        <Style Selector="ComboBox">
            <Setter Property="Foreground" Value="#333333"/>
            <Setter Property="Background" Value="#FFFFFF"/>
            <Setter Property="BorderBrush" Value="#CCCCCC"/>
            <Setter Property="BorderThickness" Value="1"/>
            <Setter Property="Padding" Value="8"/>
            <Setter Property="FontSize" Value="14"/>
            <Setter Property="CornerRadius" Value="8"/>
            <Setter Property="BoxShadow" Value="0 2px 4px rgba(0, 0, 0, 0.1)"/>
        </Style>
        <Style Selector="Button">
            <Setter Property="Foreground" Value="#FFFFFF"/>
            <Setter Property="Background" Value="#0078D7"/>
            <Setter Property="BorderBrush" Value="#0078D7"/>
            <Setter Property="BorderThickness" Value="1"/>
            <Setter Property="Padding" Value="12"/>
            <Setter Property="FontSize" Value="14"/>
            <Setter Property="CornerRadius" Value="8"/>
            <Setter Property="BoxShadow" Value="0 2px 4px rgba(0, 0, 0, 0.1)"/>
            <Setter Property="Cursor" Value="Pointer"/>
            <Setter Property="Transitions">
                <Transitions>
                    <Transitions.BoxShadow>
                        <BoxShadowTransition Duration="0:0:0.2"/>
                    </Transitions.BoxShadow>
                    <Transitions.Background>
                        <BrushTransition Duration="0:0:0.2"/>
                    </Transitions.Background>
                </Transitions>
            </Setter>
            <Setter Property="PointerOverBackground" Value="#005A9E"/>
            <Setter Property="PressedBackground" Value="#004C87"/>
        </Style>
        <Style Selector="ListBox">
            <Setter Property="Background" Value="#FFFFFF"/>
            <Setter Property="BorderBrush" Value="#CCCCCC"/>
            <Setter Property="BorderThickness" Value="1"/>
            <Setter Property="Padding" Value="10"/>
            <Setter Property="FontSize" Value="14"/>
            <Setter Property="CornerRadius" Value="8"/>
            <Setter Property="BoxShadow" Value="0 2px 4px rgba(0, 0, 0, 0.1)"/>
        </Style>
        <Style Selector="MenuItem">
            <Setter Property="Foreground" Value="#333333"/>
            <Setter Property="Background" Value="#FFFFFF"/>
            <Setter Property="BorderBrush" Value="#CCCCCC"/>
            <Setter Property="BorderThickness" Value="1"/>
            <Setter Property="Padding" Value="8"/>
            <Setter Property="FontSize" Value="14"/>
            <Setter Property="CornerRadius" Value="4"/>
            <Setter Property="PointerOverBackground" Value="#EAEAEA"/>
        </Style>
    </Window.Styles>

    <DockPanel Background="#F9F9F9">
        <!-- Верхняя панель с комбобоксами -->
        <StackPanel DockPanel.Dock="Top" 
                    HorizontalAlignment="Center" 
                    Margin="20" 
                    Spacing="15">
            <!-- Первый ComboBox для выбора группы -->
            <ComboBox ItemsSource="{Binding Groups}" 
                      SelectedValue="{Binding SelectedGroupItem}" 
                      HorizontalAlignment="Center" 
                      Width="300">
                <ComboBox.ItemTemplate>
                    <DataTemplate>
                        <TextBlock Text="{Binding Name}" />
                    </DataTemplate>
                </ComboBox.ItemTemplate>
            </ComboBox>

            <!-- Второй ComboBox для выбора способа сортировки -->
            <ComboBox ItemsSource="{Binding SortOptions}" 
                      SelectedItem="{Binding SelectedSortOption}" 
                      HorizontalAlignment="Center" 
                      Width="300">
                <ComboBox.ItemTemplate>
                    <DataTemplate>
                        <TextBlock Text="{Binding}" />
                    </DataTemplate>
                </ComboBox.ItemTemplate>
            </ComboBox>
        </StackPanel>

        <!-- Нижняя панель с кнопками -->
        <StackPanel DockPanel.Dock="Bottom" 
                    HorizontalAlignment="Center" 
                    VerticalAlignment="Center" 
                    Margin="20" 
                    Spacing="15">
            <Button Content="Удалить всех студентов" 
                    Command="{Binding RemoveAllStudentsCommand}" 
                    HorizontalAlignment="Center" 
                    Width="250"/>
            <Button Content="Добавить студента" 
                    Command="{Binding AddStudentCommand}" 
                    HorizontalAlignment="Center" 
                    Width="250"/>
        </StackPanel>

        <!-- Центральная панель для списка студентов -->
        <ListBox ItemsSource="{Binding Users}"
                 HorizontalAlignment="Center"
                 Width="400"
                 Margin="20"
                 SelectionMode="Multiple"
                 SelectedItems="{Binding SelectedUsers}">
            <ListBox.ItemTemplate>
                <DataTemplate>
                    <StackPanel Orientation="Horizontal" Margin="5">
                        <TextBlock Text="{Binding Name}" VerticalAlignment="Center" />
                    </StackPanel>
                </DataTemplate>
            </ListBox.ItemTemplate>

            <ListBox.ContextMenu>
                <ContextMenu>
                    <MenuItem Header="Удалить" Click="OnDeleteUserClick"/>
                    <MenuItem Header="Редактировать" Click="OnEditUserClick"/>
                </ContextMenu>
            </ListBox.ContextMenu>
        </ListBox>
    </DockPanel>
</Window>