Ever wondered how a computer actually works? What a CPU is actually built of? And if it's possible to build one using only CSS? If so, this talk is for you. We’ll break down the fundamentals of a CPU and rebuild them entirely in pure CSS. Using clever selectors and advanced styling tricks, we’ll construct working logic gates and even assemble them into a functional calculator. No JavaScript, no magic, just CSS pushing the boundaries of what’s possible. Slides: https://amitsh.com/links/cssday2025 *** A session from CSS Day, the CSS conference. Each June in Amsterdam; see https://cssday.nl for more information. Conference announcements in your inbox? https://cssday.nl/subscribe