Wavy header with shadow css - html

Question

Could some one bring me on track? How could I make that wave on the bottom of the header?
This is what I have so far: https://codepen.io/zimex/pen/XaQjZL
<header id="header">
<div class="container">
<div class="logo">
</div>
<div class="mobile-wrap">
<div class="inner">
<div class="user">
<div class="wrap">
<span>Hi</span>
</div>
</div>
<div class="nav">
<ul>
<li>Menu</li>
<li>Items</li>
<li>Are</li>
<li>Located</li>
<li>Here</li>
</ul>
</div>
</div>
</div>
<div class="burger">
<span></span>
</div>
</div>
</header>

Answer 1

1) you can use img for this - bad solution but work
2) check http://dev.wavemaker.com/wiki/bin/wmdoc_6.3/CSS
3)
html, body {
height: 100%;
}
html {
background: #eee;
}
body {
display: flex;
justify-content: center;
align-items: center;
}
.box {
width: 300px;
height: 300px;
border-radius: 5px;
box-shadow: 0 2px 30px rgba(black, .2);
background: lighten(#f0f4c3, 10%);
position: relative;
overflow: hidden;
transform: translate3d(0, 0, 0);
}
.wave {
opacity: .4;
position: absolute;
top: 3%;
left: 50%;
background: #0af;
width: 500px;
height: 500px;
margin-left: -250px;
margin-top: -250px;
transform-origin: 50% 48%;
border-radius: 43%;
animation: drift 3000ms infinite linear;
}
.wave.-three {
animation: drift 5000ms infinite linear;
}
.wave.-two {
animation: drift 7000ms infinite linear;
opacity: .1;
background: yellow;
}
.box:after {
content: '';
display: block;
left: 0;
top: 0;
width: 100%;
height: 100%;
background: linear-gradient(to bottom, rgba(#e8a, 1), rgba(#def, 0) 80%, rgba(white, .5));
z-index: 11;
transform: translate3d(0, 0, 0);
}
.title {
position: absolute;
left: 0;
top: 0;
width: 100%;
z-index: 1;
line-height: 300px;
text-align: center;
transform: translate3d(0, 0, 0);
color: white;
text-transform: uppercase;
font-family: 'Playfair Display', serif;
letter-spacing: .4em;
font-size: 24px;
text-shadow: 0 1px 0 rgba(black, .1);
text-indent: .3em;
}
#keyframes drift {
from { transform: rotate(0deg); }
from { transform: rotate(360deg); }
}
sample