.

app/page.tsx

@@ -25,7 +25,7 @@
 
 import Image from "next/image";
 import Link from "next/link";
-import { useEffect, useMemo, useState } from "react";
+import { useEffect, useLayoutEffect, useMemo, useState } from "react";
 import { site } from "@/content";
 import { openCookieBanner } from "@/components/CookieBanner";
 
@@ -42,23 +42,18 @@ export default function HomePage() {
   //  pointer    — the mouse position (in % of page width/height). Used by the
   //               soft glow that follows the cursor in the background.
   // ---------------------------------------------------------------------------
-  const [showIntro, setShowIntro] = useState(() => {
-    if (typeof document === "undefined") return false;
-    return document.documentElement.dataset.showIntro === "1";
-  });
+  const [showIntro, setShowIntro] = useState(false);
   const [pointer, setPointer] = useState<PointerState>({ x: 50, y: 22 });
 
   // ---------------------------------------------------------------------------
   //  INTRO OVERLAY EFFECT
   //  Plays the animated logo + wordmark the first time someone visits the
-  //  site in this browser tab. We decide before hydration whether to play it,
-  //  which avoids the homepage flashing briefly before the intro appears.
-  //  After the user accepts cookies on their first visit, we trigger the intro
-  //  immediately from the banner close action.
+  //  site in this browser tab. The initial check runs in useLayoutEffect so
+  //  the intro can mount before the first browser paint, avoiding a visible
+  //  flash of the homepage underneath.
   // ---------------------------------------------------------------------------
-  useEffect(() => {
+  useLayoutEffect(() => {
     function playIntro() {
-      document.documentElement.dataset.showIntro = "1";
       setShowIntro(true);
       try {
         window.sessionStorage.setItem(INTRO_SEEN_KEY, "true");
@@ -67,7 +62,6 @@ export default function HomePage() {
       }
 
       const timer = window.setTimeout(() => {
-        document.documentElement.dataset.showIntro = "0";
         setShowIntro(false);
       }, 3950);
 
@@ -79,21 +73,14 @@ export default function HomePage() {
     try {
       const introSeen = window.sessionStorage.getItem(INTRO_SEEN_KEY);
       const consent = window.localStorage.getItem("novarix-cookie-consent");
-      const shouldPlayNow =
-        document.documentElement.dataset.showIntro === "1" &&
-        consent === "ack" &&
-        !introSeen;
+      const shouldPlayNow = consent === "ack" && !introSeen;
 
       if (shouldPlayNow) {
         timer = playIntro();
       } else {
-        document.documentElement.dataset.showIntro = "0";
-        // eslint-disable-next-line react-hooks/set-state-in-effect
         setShowIntro(false);
       }
     } catch {
-      document.documentElement.dataset.showIntro = "0";
-      // eslint-disable-next-line react-hooks/set-state-in-effect
       setShowIntro(false);
     }