Pure, as opposed to using a library like jQuery. Plain would have been a better word.

All of the 11x11y squares are empty, the south ones are just black instead of white. I've not worked out why yet.

Somebody in another forum pointed out that 1111 is the next comic.

I wrote up something that actually demonstrates the idea of matching :checked elements to change the state of another element. Think styleable checkboxes!

http://jsfiddle.net/3CUvm/