calc() keywordsThe e, pi, infinity, and NaN keywords represent well-defined constants accepted in CSS math functions such as calc().cssCSSwidely2023-06-062025-12-06https://drafts.csswg.org/css-values-4/#calc-keywordshttps://developer.mozilla.org/docs/Web/CSS/Reference/Values/calc-keywordcss.types.calc-keywordcss.types.calc-keyword.NaNcss.types.calc-keyword.ecss.types.calc-keyword.infinitycss.types.calc-keyword.pihttps://nowyoucanuse.com/features--calc-constants.html