perspective whay des'nt work

Question

div.empty-div {
position: relative;
height: 200px;
width: 200px;
margin: 30px;
padding: 10px;
border: 1px solid black;
perspective: 100px;
-webkit-perspective: 100px;
}
div.green-div {
padding: 60px;
position: absolute;
background-color: #8bc34a;
border: 1px solid white;
transform: rotateX(45deg);
-webkit-transform: rotateX(45deg);
}

Answer 1

link the code