Font style is not affected in Mobile view in UWP - windows

Question

I am working on windows universal platform app for windows-10.I designed my whole app and use a two font style in whole application.
1)Utsaah
2)Raavi
both font family properly working in desktop and tablate view.But when i run my app in emulator (Mobile view) that time both fonts are not affacted to my textblock means default font of mobile initialize so please suggest me a solution . I just attached screenshot also code.
Code:
<Grid HorizontalAlignment="Stretch">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"></ColumnDefinition>
<ColumnDefinition Width="*"></ColumnDefinition>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="auto"></RowDefinition>
<RowDefinition Height="auto"></RowDefinition>
<RowDefinition Height="auto"></RowDefinition>
<RowDefinition Height="auto"></RowDefinition>
<RowDefinition Height="auto"></RowDefinition>
<RowDefinition Height="auto"></RowDefinition>
<RowDefinition Height="auto"></RowDefinition>
<RowDefinition Height="auto"></RowDefinition>
<RowDefinition Height="auto"></RowDefinition>
<RowDefinition Height="auto"></RowDefinition>
<RowDefinition Height="auto"></RowDefinition>
</Grid.RowDefinitions>
<StackPanel x:Name="topbar" Background="#FFF4F4F4" Grid.Row="0" Grid.ColumnSpan="2">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="auto"></ColumnDefinition>
<ColumnDefinition Width="*"></ColumnDefinition>
</Grid.ColumnDefinitions>
<Button x:Name="back_deatil_button" Grid.Column="0" Click="back_deatil_button_Click" Background="Transparent" Style="{StaticResource ButtonStyle1}">
<Image Source="Images/bback_icon#2x.png" Height="25" Stretch="Fill"></Image>
</Button>
<TextBlock x:Name="product_details" Grid.Column="1" FontSize="14" Text="PRODUCT DETAILS" Foreground="#FFF05929" FontFamily="Raavi" FontWeight="Bold" HorizontalAlignment="Center" VerticalAlignment="Center" ></TextBlock>
</Grid>
</StackPanel>
<StackPanel x:Name="product_detail" Grid.ColumnSpan="2" Margin="0,10,0,10" Grid.Row="1" HorizontalAlignment="Center" VerticalAlignment="Center">
<TextBlock x:Name="ProductName" FontSize="16" FontFamily="utsaah" VerticalAlignment="Center" HorizontalAlignment="Center" FontWeight="Bold"></TextBlock>
</StackPanel>
<Image Source="Images/top_large_shhadow.png" Grid.ColumnSpan="2" Grid.Row="2" VerticalAlignment="Top"></Image>
<StackPanel x:Name="product_img" Grid.ColumnSpan="2" Grid.Row="2" HorizontalAlignment="Center" VerticalAlignment="Top" Height="137" Margin="40,0,54,20" Width="239">
<Image x:Name="ProductImage" Source="{Binding image}" Height="137" Width="239" Margin="5"></Image>
</StackPanel>
<Image Source="Images/Products/top_large_shadow.png" Grid.ColumnSpan="2" Grid.Row="2" VerticalAlignment="Bottom"></Image>
<TextBlock Text="SKU :" Grid.Row="3" Grid.Column="0" HorizontalAlignment="Center" FontWeight="Bold" FontFamily="Utsaah" FontSize="14"></TextBlock>
<TextBlock x:Name="SKU" Grid.Row="3" Grid.Column="1" HorizontalAlignment="Left" FontFamily="Utsaah" FontSize="14"></TextBlock>
<Image Source="Images/Products/top_large_shadow.png" Margin="0,25,0,0" Grid.ColumnSpan="2" Grid.Row="3" VerticalAlignment="Bottom"></Image>
<TextBlock Text="Price :" Grid.Row="4" Grid.Column="0" HorizontalAlignment="Center" FontFamily="Utsaah" FontSize="14" FontWeight="Bold"></TextBlock>
<TextBlock x:Name="Price" Grid.Row="4" Grid.Column="1" HorizontalAlignment="Left" FontFamily="Utsaah" FontSize="14"></TextBlock>
<Image Source="Images/Products/top_large_shadow.png" Margin="0,25,0,0" Grid.ColumnSpan="2" Grid.Row="4" VerticalAlignment="Bottom"></Image>
<TextBlock Text="Qty :" x:Name="RowTotalQty" FontFamily="Utsaah" FontSize="14" Grid.Row="5" Grid.Column="0" HorizontalAlignment="Center" FontWeight="Bold"></TextBlock>
<TextBlock x:Name="TotalQty" Grid.Row="5" Grid.Column="1" HorizontalAlignment="Left" FontFamily="Utsaah" FontSize="14"></TextBlock>
<Image Source="Images/Products/top_large_shadow.png" Margin="0,25,0,0" Grid.ColumnSpan="2" Grid.Row="5" VerticalAlignment="Bottom"></Image>
<TextBlock Text="Special Price :" x:Name="RowSpecialPrice" Grid.Row="6" Grid.Column="0" HorizontalAlignment="Center" FontFamily="Utsaah" FontSize="11"></TextBlock>
<TextBlock x:Name="SpecialPrice" Grid.Row="6" Grid.Column="1" HorizontalAlignment="Left" FontFamily="Utsaah" FontSize="14"></TextBlock>
<Image Source="Images/Products/top_large_shadow.png" Margin="0,25,0,0" Grid.ColumnSpan="2" Grid.Row="6" VerticalAlignment="Bottom" ></Image>
<TextBlock Text="Status :" x:Name="RowStatus" Grid.Row="7" FontFamily="Utsaah" FontSize="14" Grid.Column="0" HorizontalAlignment="Center" FontWeight="Bold"></TextBlock>
<TextBlock x:Name="Status" Grid.Row="7" Grid.Column="1" FontFamily="Utsaah" FontSize="14" HorizontalAlignment="Left"></TextBlock>
<Image Source="Images/ttop_large_shadow.png" Margin="0,25,0,0" Grid.ColumnSpan="2" Grid.Row="7" VerticalAlignment="Bottom"></Image>
<TextBlock Text="Type :" FontFamily="Utsaah" x:Name="row_type" FontSize="14" Grid.Row="8" Grid.Column="0" HorizontalAlignment="Center" FontWeight="Bold"></TextBlock>
<TextBlock x:Name="ProductType" Grid.Row="8" FontFamily="Utsaah" FontSize="14" Grid.Column="1" HorizontalAlignment="Left"></TextBlock>
<Image Source="Imagesttop_large_shadow.png" Margin="0,25,0,0" Grid.ColumnSpan="2" Grid.Row="8" VerticalAlignment="Bottom"></Image>
<TextBlock Text="Associated :" Grid.Row="10" FontFamily="Utsaah" FontSize="14" Grid.Column="0" FontWeight="Bold" HorizontalAlignment="Center" x:Name="associated_prpduct" Visibility="Collapsed"></TextBlock>
<TextBlock x:Name="Associated" Grid.Row="10" FontFamily="Utsaah" FontSize="14" Grid.Column="1" HorizontalAlignment="Left" TextWrapping="Wrap" ScrollViewer.VerticalScrollBarVisibility="Visible" ScrollViewer.IsVerticalRailEnabled="True"></TextBlock>
<Image Source="Images/Products/top_large_shadow.png" x:Name="row_total_qty_shadow" Margin="0,25,0,0" Grid.ColumnSpan="2" Grid.Row="9" VerticalAlignment="Bottom"></Image>
<TextBlock Text="Description :" FontFamily="Utsaah" x:Name="row_description" FontSize="14" Grid.Row="9" Grid.Column="0" HorizontalAlignment="Center" FontWeight="Bold"></TextBlock>
<StackPanel Grid.Column="1" Grid.Row="9" x:Name="pnl_description" Height="auto">
<ScrollViewer HorizontalAlignment="Stretch" VerticalAlignment="Bottom" Height="50" VerticalScrollBarVisibility="Auto" Margin="0,0,0,6">
<TextBlock x:Name="Description" FontFamily="Utsaah" FontSize="14" Grid.Column="1" TextWrapping="Wrap" HorizontalAlignment="Stretch" Margin="0,0,10,0"></TextBlock>
</ScrollViewer>
</StackPanel>
</Grid>
<ProgressBar Name="mobile_back_loader" Visibility="Collapsed" IsIndeterminate="True" Foreground="#FFF05A2A" HorizontalAlignment="Stretch" Height="40" VerticalAlignment="Top" Margin="0,150,0,0" Grid.RowSpan="2"/>
</Grid>
Image:

Answer 1

Here is a list of 'recommended' fonts for UWP apps.
Guidelines for fonts
https://msdn.microsoft.com/windows/uwp/controls-and-patterns/fonts
These fonts are guaranteed to be available in all Win10 device families - desktop, mobile, iot, etc.
But, Utsaah and Raavi are not listed in the list.
The doc says:
Note If you use a font that's not in this list, your app may trigger
an automatic download of the font data from a Microsoft service.
and
UWP apps that will available on mobile devices should never use fonts for UI
content other than fonts in this list.
It's not recommended. :(