@tuanphan
thank you so so much! Works perfectly!
If you had one more moment, I have a landing page:
https://www.hightideldn.com/
And I'd love it that the the photo and the button fill one screen (so without the need for scrolling). At the moment I've just forced it to be small, but it doesn't work great.
If you had anysolution that would be amazing.
(Also thank you for all your comments on here - I've been using them for a number a different sites. You are so generous and I'm so grateful.)