When using Inspect in Chrome, want to save CSS locally so I can experiment

I’m a designer and I’m working with a web developer on a site. I don’t have a dev environment and don’t plan to get one. I want to experiment with the site’s CSS to improve the design, but any changes I make get wiped out when I switch to a new page on the site. Is there a way to save my CSS and HTML changes locally without having to save them back to a server?