Not to worry. I found a website that gives a code to make my banner responsive.
I can't see a way to delete the post.
Hello 
I have a banner on my site in the Main Page promo block. It looks fine on my laptop, but I'm wondering why it isn't displaying correctly on other devices.
It's a long, horizontal banner and on my phone I have to scroll to view it in full.
I'm sure it's probably something that I have done wrong!
If you need to check it out, the site is flauntitvintage.co.uk
