.main
{
height: 300px;
width: 100%;
background-color: #c6c6c6;
}
.top, .top::after
{
display: block;
width: 200px;
height: 200px;
}
.top
{
margin: 0 auto;
position: relative;
background-color: #6a56ff;
top: 50px;
left: 50px;
}
.top::after
{
content: '';
position: absolute;
background-color: #ffcb56;
top: -50px;
left: -50px;
}