Please see the dojo example I have set up at: https://dojo.telerik.com/AYUrAZOJ/3
The example is working exactly how I want it to with the exception that the height of the .nav-toolbar shrinks when I make .navigation-pane a flex container. I have added another toolbar just to the right of the .nav-toolbar to show the size difference. If you were to remove the styles for .navigation-pane and .nav-content the .nav-toolbar sizes as expected.
I am hoping there is a flex css value I am missing, but after about an hour of research and trying different things I have not found anything that gets the toolbar to maintain its original height. Any help would be greatly appreciated.
Please let me know if any further clarification is needed.