Impressive. While I appreciate the effort and the fact that is is more of an experiment than a production-ready package, it does seem like an odd choice to go with fixed-size pixels instead of something relative, like ems or percentages. Regardless, well done. Don't let my typical-to-HN negative tone take away from the accomplishment of this.
px is a size supposed to be fixed size in the eye of the beholder, but relative to the size and the density of the display.