Thank you! I’ve made some progress. I’ve done what you said and now the image on the right is almost at the edge of the screen but there is still a tiny gap and I’m not sure why.
I would also like to have either some padding to the left of the left-hand column so that it’s not right up on the left side of the screen. If you would be so kind as to take another look at the example you’ll see what I mean.