This is a lovely little utility from Chris Coyier that turns CSS custom properties into a live control panel.

It’s one of those tools that immediately makes me want to crack open a demo and start playing. What’s especially nice is that it doesn’t ask you to invent some parallel configuration universe if you don’t want to; it can just inspect the variables you already have and give you a UI for experimenting with them. That makes it feel less like a framework and more like a really practical enhancement to the way many of us already work.