juless

@Beyondspace Thank you for your answer! and yes i have no choice..
Can't i just detect when i use an anchor point ? I have no idea how to use javascript to fix this...

Your CSS code only works when the Dom element of the header adds the class shrink. I figured out that when you use anchor link, the viewpoint move to your link position. Howerver, the header is still not updated with shrink class.

If you insist on this effect, I think we need some additional javascript to get through it