Probably not the first to have this idea, but, “what if….”
What if there was an Apache mod that let all web-devs target WebKit with HTML/CSS and on the fly translated the CSS to support whatever quirks the requesting browser/User-Agent might have.
I’d pay handsomely to target 1 desktop browser, 1 mobile browser, etc. Let some crazy auto-updating plugin handle the rest, and I’d pay a ridiculous monthly amount for it.
If you build this, please email me!