diff --git a/src/components/layout/main.less b/src/components/layout/main.less
index 5e4bc9e..a3cac6e 100644
--- a/src/components/layout/main.less
+++ b/src/components/layout/main.less
@@ -157,12 +157,14 @@
 
         &.ant-menu-vertical {
           .ant-menu-sub {
+            height: 0;
             opacity: 0;
-            transition: none;
+            overflow: hidden;
           }
-
+          
           .ant-menu-submenu-active {
             .ant-menu-sub {
+              height: auto;
               opacity: 1;
             }
           }