From b60255f01053a9cdbe77a61f4c882fa20e65e195 Mon Sep 17 00:00:00 2001 From: DrDrij Date: Tue, 8 Sep 2026 21:27:25 +0700 Subject: [PATCH] docs: correct the FOUC mechanism in the critical-CSS and guard comments MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The CRITICAL_CSS comment in app/root.tsx and the fouc.spec.ts header both said WebKit paints the freshly-navigated document for ~1 frame before the head stylesheets apply. The v2.5.0 review found otherwise, and probing confirms it: WebKit holds first paint until the render-blocking stylesheets apply. A rAF-from-document-start sampler against the static build never caught an unstyled frame — cold or warm cache, across every fixture page, even with all CSS responses delayed by 800ms. The flash the critical CSS guards against comes ~200ms AFTER first paint instead, when React hydration fails (#418/#423) and the recovery client render re-patches whatever diverged. A head-level divergence re-creates head nodes (#126 measured a missing