Sneaky Header Blocker Trick

This article explains a subtle but satisfying visual effect on a blog's sticky header, where the background color changes from transparent to opaque as the user scrolls. The trick uses no JavaScript, relying entirely on CSS positioned layout with sticky 'blocker' elements that sit behind the header. The author breaks down the core concept, demonstrates how sticky positioning behaves within containers, and provides a minimum viable reproduction. It's a technical tutorial focused on CSS layout techniques for web development.