box radius and rectangle animation using css



this code make a radius and rectangle i make this using css keyframes animation




<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Document</title>
</head>
<body>
  <div class="box">
    
  </div>
</body>
</html>                    
                  
                



.box{
  height:200px;
  width:200px;
  background-color:green;
  position: relative;
  left:45%;
  animation: anim 5s infinite;
}
@keyframes anim {
  50%{
    border-radius:50%;
    background-color:red;
  }
}