Jquery Id Selector

<!DOCTYPE html>
<html>
  <head>
    <script src="../../ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
  </head>
  <body>
    <h1 id="myh1"> this heading have blue color </h1>
    <script>
      $("document").ready(function(){
         var h1 = $("#myh1");
        h1.css("color","blue");
      })
    </script>
  </body>

    
</html>