Change position of search box

Hi there

I'm wondering whether you can help me change the position of the search box - it's opening above the search icon, I think because of the tagline I've added in there but I can't work out how to move it.

The client wants it to open below but I think even if I can only get it to open along the same line (the default behaviour I think) then that would be sufficient.

https://movingonasthma.org.uk/

Thanks
Lucy