Run Example

Edit This Code:

<!DOCTYPE html>
<html>
 <head>
  <title> Page Title </title>
  <style type="text/css">
  h1.class_name {
   background: green;
   font-size: 24px;
   color: #fff;
   }  
 </style>
 </head>

 <body>
  <h1 class="class_name"> Changing a specific element under a class. </h1>
 </body>
</html>

Result: