body {
    color:blue;
    font-size: 23px;
}

header {
    font-size: 30px;
    text-align: center;
}

ul {
    list-style-type: none;
    margin: 0;
    padding: 0;
    overflow: hidden;
    background-color: #333;
}

#nav li {
        
float: left;
}
    
li a {
    display: block;
    color: white;
    text-align: center;
    padding: 14px 16px;
    text-decoration: none;
    font-size: 20px;
}

li a:hover {
    background-color: #111;
}

html {
    background-color: lightgrey;
}