body {
    font-family: Arial, sans-serif;
    margin: 0;
}

header {
    background: #333;
    color: white;
    padding: 15px;
    text-align: center;
}

nav {
	text-align: center;
	position: -webkit-sticky;
    position: sticky;
    top: 0;
    font-family: Helvetica;
}

nav ul {
	list-style-type: none
	padding: 0;
	margin: 0;
	overflow: hidden;
	background-color: #00FFFF;
}

nav li {
	display: inline-block;
	color: fuchsia;
	padding: 2px;
    text-decoration: none;
}

nav li a:hover {
    background-color: #BFFFF4;
    color: #38D660;
}

nav ul li a:hover {
    color: yellow;
}

main {
    padding: 20px;
}

section {
    margin-bottom: 30px;
}

img {
    width: 200px;
}

footer {
    background: #333;
    color: white;
    text-align: center;
    padding: 10px;
}

/* ONE MEDIA QUERY */
@media (max-width: 768px) {
    nav ul {
        flex-direction: column;
    }

    img {
        width: 100%;
    }
}