div{
      width:480px;
      margin:0px auto;
      padding: auto;
      background-color:#D9EAF3;
      text-align: center;
      }


#expandbox {
background-color: #D9EAF3;
width:400px;
height: 450px;
border: 2px dotted #E6E6FA;
overflow: hidden;
transition-duration; 0.2s
}
button {
color: pink
}
#expandbox.cls {
height: fit-content;
}