diff --git a/app.js b/app.js
index ad75b9e..5410dec 100644
--- a/app.js
+++ b/app.js
@@ -38,12 +38,16 @@ const MODES = {
 };
 
 syncViewportHeight();
+window.addEventListener("load", syncViewportHeight);
 window.addEventListener("resize", syncViewportHeight);
+window.addEventListener("scroll", syncViewportHeight, { passive: true });
 window.addEventListener("pageshow", syncViewportHeight);
 window.addEventListener("orientationchange", syncViewportHeight);
 window.visualViewport?.addEventListener("resize", syncViewportHeight);
 window.visualViewport?.addEventListener("scroll", syncViewportHeight);
 window.setTimeout(syncViewportHeight, 0);
+window.setTimeout(syncViewportHeight, 150);
+window.setTimeout(syncViewportHeight, 400);
 window.requestAnimationFrame(() => {
   window.requestAnimationFrame(syncViewportHeight);
 });
@@ -91,7 +95,14 @@ switch (PAGE) {
 }
 
 function syncViewportHeight() {
-  const viewportHeight = window.visualViewport?.height ?? window.innerHeight;
+  const visibleHeight = window.visualViewport?.height ?? window.innerHeight;
+  const viewportTopOffset = window.visualViewport?.offsetTop ?? 0;
+  const viewportHeight = Math.max(
+    visibleHeight + viewportTopOffset,
+    window.innerHeight,
+    document.documentElement.clientHeight,
+  );
+
   document.documentElement.style.setProperty("--app-viewport-height", `${Math.round(viewportHeight)}px`);
 }