Position of image and footer

I try to finish the Wikipedia Viewer project. I got two major problems with it. First one: the Wikipedia logo seems not to be centered between the h2 and lower search-navigation elements. Looks like the search-navigation has weird padding and I can’t remove it.
Second issue is concerning footer. I can’t really manipulate the height of it. It’s set as flex-item but it has like fixed height and it changes a bit when resizing the window.

Here’s my codepen: https://codepen.io/icelandico/full/vjegwb/

What to do with this issues?