how to keep the same height of the header

how to keep the same height of the header

Hi !

I would like to keep the height of the header in desktop mode and mobile mode .


- When I am enlarging the size of my browser, the header image becomes higher.
- And when I am reducing the size of my browser, the header image becomes thin.. I prefer this presentation and I would like to keep this small height...

Did you get what I said ? lol

Thank you very much for your help guys...