<!-- HTML -->
<header>
<nav>
<ul>
<li><a href="Menu.html" style="padding: 0 20px 0 20px;">Menu</a></li>
<li><a href="Burritos.html" style="padding: 0 20px 0 20px;">Burritos</a></li>
<li><a href="index.html"><img class="header-image" src="assets/Headerlogo1.png"></a></li>
<li><a href="Contact.html" style="padding: 0 20px 0 20px;">Contact Us</a></li>
<li><a href="About.html" style="padding: 0 20px 0 20px;">About Us</a></li>
</ul>
</nav>
<div id="wrapper"></div>
</header>
<!-- CSS -->
<style>
header {
background-image: url(img/your-img.jpg);
background-size: cover;
background-position: center;
height: 100vh; /* or whatever you wish */
background-attachment: fixed;
position: relative;
}
.wrapper {
position: absolute;
width: 1140px; /* or how much do you want */
top: 50%;
left: 50%;
-webkit-transform: translate(-50%, -50%);
-ms-transform: translate(-50%, -50%);
transform: translate(-50%, -50%);
}
</style>