APIVisualExecutor/Nodify/Themes/Styles/Node.xaml

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                    xmlns:local="clr-namespace:Nodify">

    <BooleanToVisibilityConverter x:Key="BooleanToVisibilityConverter" />

    <DataTemplate x:Key="DefaultInputConnectorTemplate">
        <local:NodeInput />
    </DataTemplate>

    <DataTemplate x:Key="DefaultOutputConnectorTemplate">
        <local:NodeOutput />
    </DataTemplate>

    <Style x:Key="DefaultHeaderContainerStyle"
           TargetType="Border">
        <Setter Property="CornerRadius"
                Value="3 3 0 0" />
        <Setter Property="Padding"
                Value="6 4 6 4" />
    </Style>

    <Style x:Key="DefaultFooterContainerStyle"
           TargetType="Border">
        <Setter Property="CornerRadius"
                Value="0 0 3 3" />
        <Setter Property="Padding"
                Value="6 4 6 4" />
    </Style>

    <Style TargetType="{x:Type local:Node}">
        <Setter Property="Background"
                Value="#2D2D30" />
        <Setter Property="ContentBrush"
                Value="#2D2D30" />
        <Setter Property="HeaderBrush"
                Value="#1E1E1E" />
        <Setter Property="FooterBrush"
                Value="#1E1E1E" />
        <Setter Property="Foreground"
                Value="White" />
        <Setter Property="BorderBrush"
                Value="Transparent" />
        <Setter Property="MinHeight"
                Value="15" />
        <Setter Property="MinWidth"
                Value="15" />
        <Setter Property="VerticalAlignment"
                Value="Top" />
        <Setter Property="HorizontalAlignment"
                Value="Center" />
        <Setter Property="VerticalContentAlignment"
                Value="Center" />
        <Setter Property="HorizontalContentAlignment"
                Value="Center" />
        <Setter Property="InputConnectorTemplate"
                Value="{StaticResource DefaultInputConnectorTemplate}" />
        <Setter Property="OutputConnectorTemplate"
                Value="{StaticResource DefaultOutputConnectorTemplate}" />
        <Setter Property="HeaderContainerStyle"
                Value="{StaticResource DefaultHeaderContainerStyle}" />
        <Setter Property="FooterContainerStyle"
                Value="{StaticResource DefaultFooterContainerStyle}" />
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type local:Node}">
                    <Border Background="{TemplateBinding Background}"
                            BorderBrush="{TemplateBinding BorderBrush}"
                            BorderThickness="{TemplateBinding BorderThickness}"
                            Padding="{TemplateBinding Padding}"
                            CornerRadius="3">
                        <Grid>
                            <Grid.RowDefinitions>
                                <RowDefinition Height="Auto" />
                                <RowDefinition Height="*" />
                                <RowDefinition Height="Auto" />
                            </Grid.RowDefinitions>

                            <!--Header-->
                            <Border Visibility="{TemplateBinding HasHeader, Converter={StaticResource BooleanToVisibilityConverter}}"
                                    Background="{TemplateBinding HeaderBrush}"
                                    Style="{TemplateBinding HeaderContainerStyle}"
                                    Grid.ColumnSpan="3">
                                <ContentPresenter ContentSource="Header" />
                            </Border>

                            <!--Body-->
                            <Border Style="{TemplateBinding ContentContainerStyle}"
                                    Grid.Row="1">
                                <Grid>
                                    <Grid.ColumnDefinitions>
                                        <ColumnDefinition Width="Auto" />
                                        <ColumnDefinition Width="*" />
                                        <ColumnDefinition Width="Auto" />
                                    </Grid.ColumnDefinitions>

                                    <!--Data IN-->
                                    <ItemsControl x:Name="PART_Input"
                                                  ItemsSource="{TemplateBinding Input}"
                                                  VerticalAlignment="{TemplateBinding VerticalAlignment}"
                                                  ItemTemplate="{TemplateBinding InputConnectorTemplate}"
                                                  Focusable="False" />

                                    <!--Content-->
                                    <Border Grid.Column="1"
                                            Padding="16 0 16 0"
                                            Background="{TemplateBinding ContentBrush}">
                                        <ContentPresenter VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
                                                          HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" />
                                    </Border>

                                    <!--Data OUT-->
                                    <ItemsControl x:Name="PART_Output"
                                                  ItemsSource="{TemplateBinding Output}"
                                                  ItemTemplate="{TemplateBinding OutputConnectorTemplate}"
                                                  VerticalAlignment="{TemplateBinding VerticalAlignment}"
                                                  HorizontalContentAlignment="Right"
                                                  Grid.Column="2"
                                                  Focusable="False" />
                                </Grid>
                            </Border>

                            <!--Footer-->
                            <Border Visibility="{TemplateBinding HasFooter, Converter={StaticResource BooleanToVisibilityConverter}}"
                                    Background="{TemplateBinding FooterBrush}"
                                    Style="{TemplateBinding FooterContainerStyle}"
                                    Grid.Row="2"
                                    Grid.ColumnSpan="3">
                                <ContentPresenter ContentSource="Footer" />
                            </Border>
                        </Grid>
                    </Border>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

</ResourceDictionary>