Resources/XAML/ResourceDictionaries/PasswordBox.xaml

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <Style x:Key="CustomPasswordBoxStyle" TargetType="{x:Type PasswordBox}">
        <Setter Property="VerticalContentAlignment" Value="Center"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type PasswordBox}">
                    <Border CornerRadius="10" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}">
                        <ScrollViewer x:Name="PART_ContentHost" Margin="0"/>
                    </Border>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
        <Setter Property="Effect">
            <Setter.Value>
                <DropShadowEffect ShadowDepth="0" Direction="0" Color="#FFF485F0" Opacity="1" BlurRadius="10" RenderingBias="Quality"/>
            </Setter.Value>
        </Setter>
        <Style.Triggers>
            <!-- Trigger to apply blur when the PasswordBox is disabled -->
            <Trigger Property="IsEnabled" Value="False">
                <Setter Property="Effect">
                    <Setter.Value>
                        <BlurEffect Radius="5"/>
                    </Setter.Value>
                </Setter>
                <!-- Reducing the opacity to further indicate that the PasswordBox is disabled -->
                <Setter Property="Opacity" Value="0.7"/>
            </Trigger>
        </Style.Triggers>
    </Style>
</ResourceDictionary>