CSS grid layout are about to explode into existence like the universe from the big bang. If you’re wondering how to get your head around it all, I recommend Rachel Andrew’s Grid by example site. It’s a really nice, step-by-step introduction to grid layout.
If you have any questions about grid layout, feel free to ask them here. I find they go in one ear and out the other at the moment. Hopefully that will change once we start to use them a bit more.