How to create this basic layout?

Hi

Looking for some advice. How would you create the layout in the screenshot below? It looks fairly basic but I’m having trouble.

I thought I had it by using absolute positioning but when I looked at the layout on a laptop screen (which has much less height) the text box gets cut. I tried using min height:100vh for the section but that’s not helping.

For such a simple layout I’m clearly missing something obvious?!

Thanks