styles/main.css

@@ -22,10 +22,10 @@ body {
 #thsf-schedule-wrapper {
   position: fixed;
   top: 0;
-  width: 80%;
+  left: 50%;
+  transform: translateX(-50%);
+  width: 50%;
   height: 100%;
-  margin-left: auto;
-  margin-right: auto;
   overflow: auto;
   background-color: #e6007e;
 }