Strong kingdoms endure because their laws are written, not remembered. Editor’s Note: This article was originally published on RandomThoughtsInTraffic.com and has been revised and expanded for StackNScroll as part of The CSS Codex series. The original edition introduced CSS variables primarily as a practical mechanism for reducing duplication within stylesheets. This revised version expands that discussion considerably, examining variables as architectural agreements that govern design systems, component behavior, and long-term maintainability. New material explores naming conventions, design token strategies, component contracts, variable inheritance, theming, and how experienced engineers use variables to build systems that remain understandable years after their original implementation. As part of this week’s theme, The Long Campaign,…