MainWindow.xaml

<Window x:Class="Budget.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:Budget"
        mc:Ignorable="d"
        Title="Budget" Height="600" Width="800" KeyUp="Window_KeyUp">
    <Grid>
        <TabControl x:Name="tabControl" HorizontalAlignment="Left" VerticalAlignment="Top">
            <TabItem Header="Ledger">
                <local:LedgerControl/>
            </TabItem>
            <TabItem Header="Categories">
                <Grid Background="#FFE5E5E5"/>
            </TabItem>
            <TabItem Header="Accounts">
                <Grid Background="#FFE5E5E5"/>
            </TabItem>
        </TabControl>

    </Grid>
</Window>