I think it would be better to hide a Border when the mouse is not over a tab by setting the Border 's BorderBrush to Transparent rather than setting its BorderThickness to zero.
If you remove the below line (border) from the IsMouseOver trigger it stops jumping and visually it doesn't really have a huge effect (in my opinion).
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.