Specificity

CSS Cascade Layers for Predictable Specificity

Specificity problems often appear gradually. A stylesheet starts with simple class selectors, then an override needs a more specific selector, then another rule adds an ID or !important, and eventually changing one component requires understanding a long chain of accidental precedence. Cascade layers give authors a separate way to express priority. Instead of making selectors stronger, you define which groups of rules are allowed to win. What a cascade layer changes CSS already resolves conflicts using several inputs, including origin, importance, layer order, specificity, and source order. @layer adds an explicit ordering step for normal author rules.