Box-component test

by sesubash

HTML

<div class="box1">
<div class="box2">
<div class="box3">
<form>
 <input type="text">
 <button type="submit">
   submit
 </button>
</form>
</div>
</div>
</div>

CSS

* {
  box-sizing: border-box;
  background: #fff;
}
.box1, .box2, .box3 {
  border: 1px solid;
}
.box1{
  width: 400px;
  height: 400px;
}
.box2{
  width: 300px;
  height: 300px;
}
.box3{
  width: 200px;
  height: 200px;
}