Actually as much as I hate CSS, from trying to implement the same subsystem of an application using flash and then reimplementing it in javascript + CSS I came to appreciate the flexibility of CSS when you want to adapt your widget to both mobile phones and computers....

You might want to look at http://cappuccino.org/ for a javascript library doing what you describe (disclaimer: also I've planned for some time to take a look at it, I haven't got around to it yet)