diff --git a/client/app.js b/client/app.js
index a2ccafa..b302c13 100644
--- a/client/app.js
+++ b/client/app.js
@@ -90,10 +90,20 @@ class GolfGame {
     }
 
     initMobileDetection() {
+        // Set --app-height custom property to actual visible viewport height.
+        // This works around Chrome Android's 100vh bug where vh includes the
+        // space behind the dynamic URL bar.
+        const setAppHeight = () => {
+            document.documentElement.style.setProperty('--app-height', `${window.innerHeight}px`);
+        };
+        window.addEventListener('resize', setAppHeight);
+        setAppHeight();
+
         const mql = window.matchMedia('(max-width: 500px) and (orientation: portrait)');
         const update = (e) => {
             this.isMobile = e.matches;
             document.body.classList.toggle('mobile-portrait', e.matches);
+            setAppHeight();
             // Close any open drawers on layout change
             if (!e.matches) {
                 this.closeDrawers();
diff --git a/client/style.css b/client/style.css
index 95cdfb2..b0e256d 100644
--- a/client/style.css
+++ b/client/style.css
@@ -4906,9 +4906,7 @@ body.screen-shake {
 }
 
 body.mobile-portrait {
-    height: 100vh;
-    height: -webkit-fill-available;
-    height: 100dvh;
+    height: var(--app-height, 100vh);
     overflow: hidden;
     overscroll-behavior: contain;
     touch-action: manipulation;
@@ -4916,19 +4914,18 @@ body.mobile-portrait {
 
 body.mobile-portrait #app {
     padding: 0;
-    height: 100%;
+    height: var(--app-height, 100vh);
     overflow: hidden;
 }
 
 /* --- Mobile: Game screen fills viewport --- */
 /* IMPORTANT: Must include .active to avoid overriding .screen { display: none } */
 body.mobile-portrait #game-screen.active {
-    position: fixed;
-    top: 0;
-    left: 0;
-    right: 0;
-    bottom: 0;
+    height: var(--app-height, 100vh);
+    max-height: var(--app-height, 100vh);
     overflow: hidden;
+    margin-left: 0;
+    width: 100%;
     display: flex;
     flex-direction: column;
 }