header

hello,
Is the a way to make the header fixed. I know about and how to setup the sticky header under layout settings-header settings. I have tried setting both to the same value that works for the most part but not without issues.
Issue 1- header jumps when scrolling
Issue 2- my logo changes size and I want it to remain the same size at all time when in the header.
please let me know the best setting for the header logo. I copied what was in the demo but the header still resizes when scrolling.

http://www.mealdata.net
ty
jb