How to get this shrink effect more smooth?

Hi, I have a sticky header where I applied a scroll shrink effect. It all works but is not so smooth. How would I get that better? Or is this the way it is?

here the live dev. site example :http://testnl.vini4all.nl/

Probably by applying a transition property on the animated elements or use jQuery.animate() with an easing.

Ok. Applying some transitions helped. Thanks.