If you don’t want your design to look like it’s made out of unrelated things, this article is for you. There is already a technology, called CSS, which is designed specifically to solve this problem. Using CSS, you can propagate styles that cross the borders of your HTML components, ensuring a consistent design with minimal effort. Today, Heydon Pickering is going to revisit inheritance, the cascade and scope here with respect to modular interface design. He aims to show you how to leverage these features so that your CSS code becomes more concise and self-regulating, and your interface more easily extensible.