diff --git a/src/components/ConnectionModal.tsx b/src/components/ConnectionModal.tsx
index 2c031fb..a94403e 100644
--- a/src/components/ConnectionModal.tsx
+++ b/src/components/ConnectionModal.tsx
@@ -113,10 +113,13 @@ function detectPlatform(): string | null {
 }
 
 function useIsMobile() {
-  const [isMobile, setIsMobile] = useState(false)
+  // Initialize synchronously to avoid flash between desktop/mobile layouts
+  const [isMobile, setIsMobile] = useState(() => {
+    if (typeof window === 'undefined') return false
+    return window.innerWidth < 768
+  })
   useEffect(() => {
     const check = () => setIsMobile(window.innerWidth < 768)
-    check()
     window.addEventListener('resize', check)
     return () => window.removeEventListener('resize', check)
   }, [])