diff --git a/css/common.css b/css/common.css
index a014cd4..2c3b8a7 100644
--- a/css/common.css
+++ b/css/common.css
@@ -109,11 +109,13 @@ body {
   overflow: auto;
   animation: hintShow 0.3s forwards;
   border: 0px solid #c4c7ce;
+  border-top-width: 0px;
   border-bottom: none;
 }
 @keyframes hintShow {
   0% {
     height: 0;
+    border-top-width: 0px;
   }
   100% {
     border-width: 1px;
diff --git a/css/common.less b/css/common.less
index 2b9a7cd..ed0af81 100644
--- a/css/common.less
+++ b/css/common.less
@@ -128,12 +128,14 @@ body {
             overflow: auto;
             animation: hintShow 0.3s forwards;
             border: 0px solid #c4c7ce;
+            border-top-width: 0px;
             border-bottom: none;
             // box-shadow: 0px 5px 5px #dfdfdf;
 
             @keyframes hintShow {
                 0% {
                     height: 0;
+                    border-top-width: 0px;
                 }
 
                 100% {