body{
 padding: 10px;
 width: 100%;
 font: 1em sans-serif;
 text-align: center;
}
nav { 
    background-color: gray;
    position: fixed;
    width: 100%;
}
nav ul li {   
    display: inline;
    margin-right: 20px;
}
header{
 background-image: url(../imgs/eyeglasscasebackgroundimage.jpg);
 width: 100%;
 text-align: center;
 font-size: large;
}
footer{
    color: gray;
}