diff --git a/source/static/css/main.css b/source/static/css/main.css
index a4ab280..ca42f6d 100644
--- a/source/static/css/main.css
+++ b/source/static/css/main.css
@@ -259,6 +259,9 @@
   top: 0;
   left: 0;
   transition: opacity 0.3s;
+  -webkit-user-select: none; /* Safari */
+  -ms-user-select: none; /* IE 10 and IE 11 */
+  user-select: none; /* Standard syntax */
 }
 
 /* Show the tooltip text when you mouse over the tooltip container */