Probably bleeding obvious CSS issue that I can't fix...
... cos I'm an idiot.
So, I'm just trying to make a simple template for a site I'm building for a charity. It just has a <header>, a <menubar>, and then a <main> content area with a <sidebar>. All this in a <wrapper> on top of a <background> div. Simple.
So why wont my chosen tone of silver-gray background color extend down the whole page?!! It only reaches down to the menubar and wont underlay the main content area although everything is inside the <background> div and it should stretch to fit, no?
I've hosted it here with all the content removed for ease of pointing out what fundamentally stupid mistake I'm making - please help!: