This document discusses the differences between CSS and JavaScript and when each is most appropriate to use. It argues that CSS is often underestimated in favor of JavaScript solutions. CSS has advanced significantly with features like calc(), media queries, animations/transitions, flexbox, grid, variables and more. These powerful features allow many tasks to be accomplished with CSS alone without needing JavaScript. The document encourages embracing the "squishiness" of the web and considering CSS more when building interfaces.