I do this code for making Wave Background but not properly curved. checked image & understand better well..............
footer{
width:100%;
height: 150px;
position: relative;
}
#wave {
position: absolute;
left: 0px;
bottom: 0;
height: 10%;
width: 100%;
border-top-left-radius: 30%;
background: rgb(206, 225, 235) none repeat scroll 0% 0%;
}
#wave::after {
content: "";
display: block;
position: absolute;
border-bottom-right-radius: 0;
border-top-left-radius: 1000%;
border-top-right-radius: 80%;
border-bottom-left-radius: 10%;
height: 100px;
background-color: rgb(206, 225, 235);
left: 0px;
bottom: 50%;
width: 100%;
}
<!-- html code -->
<footer>
<div id="wave"></div>
</footer>