Dropping Astro's ClientRouter for web standards

Astro ships a built-in SPA router called ClientRouter. It intercepts navigations, swaps the DOM in JavaScript, and fires its own lifecycle events — giving you smooth transitions, prefetching, and persistent elements across page loads. For a complex app with shared state across routes, that JavaScript layer earns its keep. For a blog, it turned out to be a JavaScript solution to problems the browser now solves in CSS and HTML. Cross-document view transitions, link prefetching, animated element morphs — all of it ships natively, with no client-side routing, no lifecycle events, and no DOM mutation on navigation. And removing the JavaScript layer fixed a real bug in the process. The trigger: iOS Safari Reader Mode iOS Safari's Reader Mode reformats pages for distraction-free reading. It works by observing the DOM and rewriting it into a clean reading view. ClientRouter works by intercepting navigations, fetching the new page's HTML, and swapping parts of the DOM in place. Those two…