1 Table of Contents: “...:In-range and :out-of-range:valid and :invalid; Selectors and Specificity; Conclusion; CSS...”

2 Table of Contents: “... organization; Specificity; Choose low-specificity selectors; Avoid chaining class selectors; Avoid using id...”

3 “... contexts, specificity, and the cascade. CSS mastery lies in understanding these concepts and how to take...”