<div class="box">
<span></span>
</div>
*{
margin:0;
padding:0;
}
.box{
width:100%;
height:200px;
background:#2a2e31;
display:block;
position:relative;
}
span{
position:absolute;
width:100%;
bottom:0;
}
span:after {
background-image: url('https://zurb.com/packs/zurb/img/curve-bg-576672200f6225a05f88cc5aabeee29f.svg');
background-size: 100% 100%;
content: "";
display: block;
height: 40px;
position: absolute;
top: -39px;
width: 100%;
z-index: 1;
}
}