Explore the world of CSS variables and conditionals in this comprehensive conference talk from CSS Day 2013. Delve into the history and modern applications of variables, discovering their various use cases and learning about conditional rules. Uncover variable hacks, hierarchies, and sprites, and gain insights into functions and nondeterministic values. Investigate subject selectors, accessing style sheets, and the intriguing concept of CSS dash values. Conclude with an examination of Shadow DOM web components and scoped style sheets, enhancing your understanding of advanced CSS techniques.