style.css

body {
    font-family: 'Trebuchet MS', 'Lucida Sans Unicode', 'Lucida Grande', 'Lucida Sans', Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: black;
    color: white;
    text-align: center;
}
img {
    max-width: 300px;
    box-shadow: 0px 0px 15px white;
}
footer {
    padding: 10px;
    background-color: #333;
    color: #fff;
}
header {
    background-color: #333;
    color: #fff;
    position: -webkit-sticky;
    position: sticky;
    top: 0;
    padding: auto;
    margin: 0;
}
nav ul {
    list-style: none;
    display: flex;
    justify-content: center;
}
nav li {
    /* margin: 0 20px; */
    padding: 20px 0;
    color: #fff;
    transition: all 0.3s;
}
nav a {
    text-decoration: none;
    margin: 20px 20px 20px 20px;
    color: inherit;
}
nav li:hover {
    background-color: #334466;
    color: #4bf;
}