copy of the parent style.css
A child theme style.css file should contain ONLY changes, not a copy of the entire file. So start by removing everything below the @import line.
Then try adding this CSS under that line:
img.header-image {
margin: 0 auto;
display: table;
}
Sorry, I missed the site you linked to – and thus the above doesn’t do what you want – it only centers the image but it’s still above the navigation. It’s likely possible to do what you are asking about, but it’s a bit more tricky – and you won’t easily be able to modify the menu items – so are those the way you want them? I’m guessing the menu should also be centered on the page.
Thank you WPyogi for all your help. I have amended my child style.css file as you suggested. I have decided moving my menu bar as i initially wanted is perhaps a little beyond my ability so have adjusted me design. Thank-you again.