Reference object inside XAML template - wpf

Question

I have resource dictionary for my radio button which adds textbox to it. I want to add trigger which adds left margin to this textbox but I don't know how to reference it
I marked place where I want to add reference
<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<Style BasedOn="{StaticResource {x:Type ToggleButton}}"
TargetType="{x:Type RadioButton}"
x:Key="MenuButtonTheme">
<Style.Setters>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="RadioButton">
<Grid VerticalAlignment="Stretch"
HorizontalAlignment="Stretch"
Background="{TemplateBinding Background}">
<TextBlock Text="{TemplateBinding Property=Content}"
VerticalAlignment="Center"
Margin="20,0,0,0">
</TextBlock>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
<Setter Property="Background" Value="Transparent"></Setter>
<Setter Property="BorderThickness" Value="0"></Setter>
</Style.Setters>
<Style.Triggers>
<Trigger Property="IsChecked" Value="True">
<Setter Property="Margin" Value="30,0,0,0"></Setter> <!-- Reference TextBlock here -->
</Trigger>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="Background" Value="#424549"></Setter>
</Trigger>
</Style.Triggers>
</Style>
</ResourceDictionary>

Answer 1

You need to set triggers not in Style, but in ControlTemplate. Then you can refer to template elements by name:
<ControlTemplate TargetType="RadioButton">
<Grid x:Name="PART_Main" VerticalAlignment="Stretch"
HorizontalAlignment="Stretch"
Background="{TemplateBinding Background}">
<TextBlock x:Name="PART_TBlock"
Text="{TemplateBinding Property=Content}"
VerticalAlignment="Center"
Margin="20,0,0,0"/>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="IsChecked" Value="True">
<Setter TargetName="PART_TBlock" Property="Margin" Value="30,0,0,0"/>
</Trigger>
<Trigger Property="IsMouseOver" Value="True">
<Setter TargetName="PART_Main" Property="Background" Value="#424549"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>