Graph Paper CSS only background

When you're working with designers and UX, it's occasionally helpful to have a grid on the page in order to help with layouts. I used to love working with graph (construction) paper when I was younger, and I thought it'd be cool to be able to do this without using a background image.

See the Pen Graph Paper CSS only background by Pete (@peterbenoit) on CodePen.

As a bonus, here's a Bookmarklet you can add to your browser so you can use it on demand. GridMe!