MainWindow.xaml

<Window
        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:CatWaterCodes_IDE"
        xmlns:dragablz="http://dragablz.net/winfx/xaml/dragablz" xmlns:mah="http://metro.mahapps.com/winfx/xaml/controls" xmlns:dockablz="http://dragablz.net/winfx/xaml/dockablz" x:Class="CatWaterCodes_IDE.MainWindow"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800">


    <DockPanel VerticalAlignment="Stretch" LastChildFill="True">

        <ToolBar HorizontalAlignment="Left" Height="25" VerticalAlignment="Top" Width="800" DockPanel.Dock="Top">
            <Menu>
                <MenuItem Header="File">
                    <Button Content="New" Click="NewFileBtn"/>
                    <Button Content="Save" Click="SaveBtn"/>
                    <Button Content="Save As..." Click="SaveAsBtn"/>
                </MenuItem>

                <MenuItem Header="Window">
                    <Button Content="New Window..." Click="NewFileBtn"/>
                    <Button Content="Generic Browser" Click="NewBrowser"/>
                    <MenuItem Header="Websites">
                        <MenuItem Header="Entertainement">
                            <Button Content="Spotify" Click="NewOpenURL" Tag="https://open.spotify.com"/>
                            <Button Content="YouTube" Click="NewOpenURL" Tag="https://www.youtu.be"/>
                            <Button Content="Netflix" Click="NewOpenURL" Tag="https://www.netflix.com"/>
                        </MenuItem>
                        <MenuItem Header="Programming">
                            <Button Content="LeetCode" Click="NewOpenURL" Tag="https://www.leetcode.com"/>
                            <Button Content="ShaderToy" Click="NewOpenURL" Tag="https://www.shadertoy.com"/>
                        </MenuItem>
                        <MenuItem Header="Tools">
                            <Button Content="GitHub" Click="NewOpenURL" Tag="https://www.github.com"/>
                            <Button Content="ChatGPT" Click="NewOpenURL" Tag="https://www.chatgpt.com"/>
                        </MenuItem>
                    </MenuItem>
                </MenuItem>
                <!--Add more toolbar items here-->
            </Menu>
        </ToolBar>

        <dockablz:Layout Partition="2AE89D18-F236-4D20-9605-6C03319038E6" Name="RootLayout"
                     FloatingItemsSource="{Binding ToolItems}"
                     FloatingItemHeaderMemberPath="Header"
                     IsFloatDropZoneEnabled="True"
                     ClosingFloatingItemCallback="{Binding ClosingFloatingItemHandler}"
                     FloatingItemsContainerMargin="0 2 0 0"
                     VerticalAlignment="Stretch"
                     VerticalContentAlignment="Stretch">

            <dockablz:Layout.BranchTemplate>
                <DataTemplate>
                    <dragablz:TabablzControl>
                        <dragablz:TabablzControl.InterTabController>
                            <dragablz:InterTabController InterTabClient="{Binding InterTabClient}" Partition="2AE89D18-F236-4D20-9605-6C03319038E6" />
                        </dragablz:TabablzControl.InterTabController>
                    </dragablz:TabablzControl>
                </DataTemplate>
            </dockablz:Layout.BranchTemplate>

            <dragablz:TabablzControl x:Name="InitialTabablzControl"
                                 FixedHeaderCount="1"
                                 AddLocationHint="After">
                <dragablz:TabablzControl.InterTabController>
                    <dragablz:InterTabController InterTabClient="{Binding InterTabClient}" Partition="2AE89D18-F236-4D20-9605-6C03319038E6" />
                </dragablz:TabablzControl.InterTabController>
            </dragablz:TabablzControl>

        </dockablz:Layout>
    </DockPanel>
</Window>