I have to develop a customized tab control and decided to create it with WPF/XAML, because I planned to learn it anyway. It should look like this when it's finished:

I made good progress so far, but there are two issues left:

1. Only the first/last tab item should have a rounded upper-left/bottom-left corner. Is it possible to modify the style of these items, similar to the way I did with the selected tab item?

2. The selected tab item should not have a border on its right side. I tried to accomplish this with z-index and overlapping, but the results were rather disappointing. Is there any other way to do this?

XAML:

<Window x:Class="MyProject.TestWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="TestWindow" Height="350" Width="500" Margin="5" Background="LightGray">
<Window.Resources>
    <Style TargetType="{x:Type TabControl}">
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type TabControl}">
                    <DockPanel>
                        <Border 
                            Margin="0,100,-1,0" 
                            Background="#FFAAAAAA"
                            BorderBrush="Gray"
                            CornerRadius="7,0,0,7"
                            BorderThickness="1">
                            <TabPanel
                                Margin="0,0,0,0"
                                IsItemsHost="True" />
                        </Border>
                        <Border
                            Background="WhiteSmoke"
                            BorderBrush="Gray"
                            BorderThickness="1"
                            CornerRadius="7,7,7,0" >
                            <ContentPresenter 
                                ContentSource="SelectedContent" />
                        </Border>
                    </DockPanel>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
    <Style TargetType="{x:Type TabItem}">
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type TabItem}">
                    <Grid>
                        <Border Name="Border" 
                            Background="#FFAAAAAA"
                            CornerRadius="7,0,0,0"
                            BorderBrush="Gray"
                            BorderThickness="0,0,0,1"
                            Margin="0,0,0,0">
                            <ContentPresenter x:Name="ContentSite"             
                                VerticalAlignment="Center"
                                HorizontalAlignment="Left"
                                ContentSource="Header"
                                Margin="10,10,10,10"/>
                        </Border>
                    </Grid>
                    <ControlTemplate.Triggers>
                        <Trigger Property="IsSelected" Value="True">
                            <Setter TargetName="Border" 
                                Property="Background" 
                                Value="WhiteSmoke" />
                        </Trigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
</Window.Resources>
<Grid>
    <TabControl Name="_menuTabControl" TabStripPlacement="Left" Margin="5">
        <TabItem Name="_tabItem1" Header="First Tab Item" ></TabItem>

        <TabItem Name="_tabItem2" Header="Second Tab Item" >
            <Grid />
        </TabItem>
        <TabItem Name="_tabItem3" Header="Third Tab Item" >
            <Grid />
        </TabItem>
    </TabControl>
</Grid>