practice/practiceApplicaiton/ClientsPage.xaml

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             x:Class="practiceApplicaiton.ClientsPage"
             Title="Клиенты">
    <Grid RowDefinitions="Auto,*,Auto" Padding="16" RowSpacing="10">

        <Grid Grid.Row="0" ColumnDefinitions="*,Auto" ColumnSpacing="8">
            <Entry x:Name="SearchEntry" Placeholder="Поиск по фамилии или телефону"
                   TextChanged="OnSearchChanged"/>
            <Button Grid.Column="1" Text="+ Добавить"
                    BackgroundColor="#4472C4" TextColor="White" CornerRadius="8"
                    Clicked="OnAddClicked"/>
        </Grid>

        <CollectionView Grid.Row="1" x:Name="ClientsList"
                        SelectionMode="Single" SelectionChanged="OnSelectionChanged">
            <CollectionView.ItemTemplate>
                <DataTemplate>
                    <Frame Margin="0,4" Padding="12" CornerRadius="8"
                           BackgroundColor="White" BorderColor="#E0E0E0">
                        <Grid ColumnDefinitions="*,Auto">
                            <VerticalStackLayout Spacing="3">
                                <Label Text="{Binding FullName}" TextColor="#4472C4"
                                       FontAttributes="Bold" FontSize="15"/>
                                <Label Text="{Binding PhoneNumber}" TextColor="#555"/>
                                <Label Text="{Binding FirmName}" TextColor="#888" FontSize="12"/>
                            </VerticalStackLayout>
                        </Grid>
                    </Frame>
                </DataTemplate>
            </CollectionView.ItemTemplate>
        </CollectionView>

        <Grid Grid.Row="2" ColumnDefinitions="*,*" ColumnSpacing="8">
            <Button Text="Редактировать" BackgroundColor="#4472C4"
                    TextColor="White" CornerRadius="8"
                    x:Name="EditButton" IsEnabled="False" Clicked="OnEditClicked"/>
            <Button Grid.Column="1" Text="Удалить"
                    BackgroundColor="#C0392B" TextColor="White" CornerRadius="8"
                    x:Name="DeleteButton" IsEnabled="False" Clicked="OnDeleteClicked"/>
        </Grid>
    </Grid>
</ContentPage>