Advice generator app with vanilla JavaScript

I was working on this project in Chrome. The Advice was being fetched perfectly. Then I went to Firefox. The Advice was being fetched only one time & not changing. I clicked the button multiple time but nothing happened. I went to the network tab & saw The request were 200. After some research, I realized that Firefox cached the response. Every time, I called the API, It gave the cached response. Then I used { cache: "no-cache" } in fetch function. Now It's working fine.

I used CSS variables to store style-guides color. But I feel uncomfortable in naming. How do you name your CSS variables?