Hi, I am interested in your project to create a scrollable sidebar with modern UI design in WPF. I have extensive experience in developing WPF applications and I am confident that I can deliver the results you require. I can create a scrollable right sidebar that covers 35% of the screen, with a top bar containing buttons. I will bind tabs inside the sidebar using the ItemsSource property and will allow the user to add a new form on the same page by creating a new object of that form. I will ensure that the design is modern and user-friendly, and that the functionality is efficient and reliable. Please let me know if you would like to discuss further. Thank you!