Update index.html

index.html

@@ -8,7 +8,7 @@
 <script src="https://code.jquery.com/jquery-3.7.1.js" integrity="sha256-eKhayi8LEQwp4NKxN+CfCh+3qOVUtJn3QNZ0TciWLP4=" crossorigin="anonymous"></script>
 
 <style>
-  .chart_box{
+  #chart_box{
     align-content: center;
     display: flex;
     flex-direction: column;