diff --git a/app/index.html b/app/index.html
index c0e2dc4..d811dc9 100644
--- a/app/index.html
+++ b/app/index.html
@@ -171,7 +171,7 @@ body {
   flex-direction: column;
   overflow-y: auto;
   z-index: 100;
-  transition: background-color 0.2s ease, transform 0.3s ease;
+  transition: background-color 0.2s ease, transform 0.3s ease, visibility 0s ease 0.3s;
 }
 
 .layout-sidebar.nav-left .sidebar { left: 0; }
@@ -738,12 +738,13 @@ body {
 
   .layout-sidebar .sidebar {
     transform: translateX(-100%);
+    visibility: hidden;
     width: 80vw;
     max-width: 320px;
     box-shadow: var(--shadow-md);
   }
   .layout-sidebar.nav-right .sidebar { transform: translateX(100%); }
-  .layout-sidebar .sidebar.open { transform: translateX(0); }
+  .layout-sidebar .sidebar.open { transform: translateX(0); visibility: visible; transition: background-color 0.2s ease, transform 0.3s ease; }
   .layout-sidebar .main-area { margin-left: 0 !important; margin-right: 0 !important; }
   .main-content { padding: 1rem 1.25rem 3rem; }