headerfixed

HTML

<div class="header">
    <audio controls>
        Your browser does not support the audio element.
    </audio>
</div>
<div class="outer">
    <span class="banner">LOGO</span>
    <div class="header">Header</div>
</div>
<div class="content">Content</div>

CSS

.header {
    background-color: #ccc;
    width: 100%;
    position: fixed;
    top: 0;
    bottom: auto;
}
.outer {
    background-color: green;
    position: relative;
    height: 100px;
}
.outer .banner {
    font-size: 46px;
}
.outer .header {
    position: absolute;
    bottom: 0;
    z-index: 2;
    top: auto;
}
.content {
    height: 1500px;
    color: blue;
    background-color: #fff;
    margin-top: 100px;
}