.holder{
	position:relative;
	width:40px;
	bacgrond-color:yellow;
}
.top{
	width: 50px;
	height:50px;
	background:red;
	border:blue solid 2px;
	border-bottom:none;
	position:relative;
	z-index:4

}
.bottom{
	z-index:2;
	width: 100px;
	height: 100px;
	position:absolute;
	top:50px;
	left:0;
	border: blue solid 2px;
	background:red;
}