I'm trying to add a background image to one part of our site, using includets. See https://www.tewinvillage.co.uk/clubs/thacsnew/

I had to make the background image transparent in order to stop it hiding the left hand column, but the links in the left hand column now don't work (unless the screen is so narrow that the background image isn't shown).

Is there a way to have a background image on a page like this?