• HTML
• CSS

HTML

<div class="box"></div>

CSS

*{
    margin:0;
    padding:0;
    box-sizing:border-box;
}
body{
    background:#24385c;
    display:flex;
    justify-content:center;
    align-items:center;
    min-height:100vh;
}
.box{
    width:160px;
    height:160px;
    background:#1abc9c;
    position:relative;
    transform:skewY(-15deg) translate(85px,0px);
}
.box:before{
    content:'';
    width:160px;
    height:160px;
    background:#17a589;
    position:absolute;
    top:-37.5px;
    left:-160px;
    transform:skewY(25deg);
}
.box:after{
    content:'';
    width: 142px;
    height: 142px;
    border-radius: 3px;
    background: #48c9b0;
    position:absolute;
    top:-108px;
    left:-70px;
    transform : rotate(60deg) skew(-30deg,-35deg);
    box-shadow:500px 475px 20px rgba(0,0,0,0.25);
;

}