diff --git a/web/client/src/sections/humanAffairs/style.less b/web/client/src/sections/humanAffairs/style.less
index 0452f69..12203ff 100644
--- a/web/client/src/sections/humanAffairs/style.less
+++ b/web/client/src/sections/humanAffairs/style.less
@@ -23,6 +23,7 @@
         .tree-icon {
             padding-left: 6px;
             opacity: 0;
+            -webkit-transition: opacity 0.1s 0.2s;
 
             .semi-icon {
                 padding-left: 6px;
@@ -31,6 +32,7 @@
 
         .tree-icon:hover {
             opacity: 1;
+            -webkit-transition: opacity 0.2s;
         }
     }