Choosing CSS Selectors for Production: Specificity, Modern Pseudo-Classes, and Maintainable Styles

A practical guide to choosing CSS selectors for production codebases. Covers a decision framework moving from type selectors to classes, attributes, combinators, and modern pseudo-classes. Explains when to use :is() for reducing repetition, :where() for zero-specificity defaults, and :has() for context-driven styling. Includes specificity rules, warnings about deep nesting creating fragile chains, selector performance guidance, real-world patterns, and common anti-patterns to avoid.