Resources/XAML/ResourceDictionaries/Page.xaml

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <Style x:Key="Page_Style"
           TargetType="{x:Type UserControl}">
        <Setter Property="RenderTransform">
            <Setter.Value>
                <TranslateTransform X="0" Y="50" />
            </Setter.Value>
        </Setter>
        <Style.Triggers>
            <Trigger Property="Visibility"
                     Value="Collapsed">
                <Setter Property="Opacity"
                        Value="0" />
            </Trigger>
            <EventTrigger RoutedEvent="Loaded">
                <BeginStoryboard>
                    <Storyboard>
                        <DoubleAnimation Storyboard.TargetProperty="Opacity"
                                         Duration="0:0:1"
                                         From="0"
                                         To="1" />
                        <DoubleAnimation Storyboard.TargetProperty="(UIElement.RenderTransform).(TranslateTransform.Y)"
                                         From="50"
                                         To="0"
                                         Duration="0:0:0.8"
                                         DecelerationRatio="0.6" />
                    </Storyboard>
                </BeginStoryboard>
            </EventTrigger>
        </Style.Triggers>
    </Style>
</ResourceDictionary>