Static variables are not always global, but global variables are almost always static, therefore dynamic variables should almost always be local. Did you follow that? If not, you might need to see my talk. I will cover HOW to use CSS variables correctly for things like: theming, responsive design, prototyping, animation and much more. A practical guide that tells you more than how the syntax works. CSSconf EU will be back on May 31st 2019: https://2019.cssconf.eu/