<meta charset="UTF-8">
<meta content="width=device-width, initial-scale=1.0" name="viewport">
<meta content="ie=edge" http-equiv="X-UA-Compatible">
<title>Document</title>
<style>
.a {
width: 500px;
height: 500px;
background: #448899;
overflow: hidden;
position: relative;
}
<pre><code>.b {
width: 100%;
height: 400px;
background: #892989;
position: absolute;
}
.c {
height: 350px;
display: flex;
align-items: center;
background: turquoise;
position: absolute;
}
.c>li {
flex-shrink: 0;
width: 200px;
height: 300px;
margin: 0 10px;
background: chocolate;
}
</code></pre>
</style>