Not to pick on the author of this mini-tutorial but this is a completely futile exercise as can be seen by the accompanying diagram outlining the building block

Not to pick on the author of this mini-tutorial but this is a completely futile exercise as can be seen by the accompanying diagram outlining the building blocks of his endeavor which was a raster graphics not HTML/CSS as he preached. You would think he would put his money where his mouth is and convert all the diagrams and vector graphics into HTML/CSS but deep down he knows it's just ridiculous and excruciatingly impractical.