Styling the Navigation: Declarative Route and Navigation Matching in CSS

One of the things in CSS that we at Chrome have been thinking about for a while now is a way to do declarative route and navigation matching in CSS. Together with Noam Rosenthal and David Baron I’ve been working on this for the past few months. After an initial introduction at the CSS Working Group back in January, and a quick feedback session with developers at CSS Day in June, we think we have something that is ready for further discussion. At next week’s CSS Working Group F2F (face-to-face) meeting in Berlin, we’ll be presenting our current line of thinking. This post is a quick intro to the concepts we’ll be covering. ~ The Problem: Knowing where you’re going If you’ve played around with View Transitions, especially for Multi-Page Apps (MPAs), you’ve probably hit a familiar wall. Very often, you want to style a page differently based on where you are coming from and where you are going to. Imagine a simple flow: When navigating from the index page to the about page, you want the…