get access to the aspruino from a website to communicate with the dom and css

Hi - do you want to control Espruino from a webpage on your PC (while it is physically connected), or do you want it to be controlled while it's powered from something else?

If you want to control Espruino from a webpage while it's plugged into the PC, you'll have to make your webpage a Chrome Web App (they have a serial api). Either that or you can serve the webpage from something like node or node-webkit, that itself will have serial support.

If you want Espruino to actually serve up a webpage, and to then be controlled by it, you'll need to plug in some way to get Espruino onto the net - there's a bunch of information about this and some examples on the Internet page.