CSS Grid: At Last, Layout Makes Sense

I've been experimenting with CSS Grid, and describing a layout in rows and columns feels much closer to the thing I'm trying to draw. That's a relief after years of working around floats.

I'm treating it as something to learn and prototype with for now, rather than assuming every browser we support is ready. The interesting test is a page with uneven content. A layout system needs to cope with the long heading as well as the neat example.