Adam, I'm not Joomshaper team member. And even if I were, these things outside the support of Joomshaper. Any customization only in the hands of the user.
As I wrote above, Header is one of the most complex elements of the site. It takes me a few hours of work when I make a responsive Header based on the design, which sent me a web-designer. There is no code that can be reached as a rabbit from a magician hat and will work. This work requiring a thought process.
Therefore, return to your previously Header and create a layout designs, as I described above. After that, I will be able to give you some CSS tips. And these actions will help you with understanding.