how to add context aware css in blogger post with jquery in 5 minutes

<Back

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script>
$(document).ready(function(){
  $("button").click(function(){
      alert("hello jquery");
  });
});
</script>


<button>alert from jquery function</button>


Example