body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

header {
    background-color: #333;
    padding: 10px 0;
}

nav ul {
    list-style-type: none;
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
}

nav ul li {
    margin: 0 15px;
}

nav ul li a {
    color: white;
    text-decoration: none;
    font-size: 18px;
}

nav ul li a:hover {
    text-decoration: underline;
}

section {
    padding: 50px;
    text-align: center;
}

#home {
    background-color: #f4f4f4;
}

#resume, #pictures, #research, #teaching, #contact {
    background-color: #e9e9e9;
    margin: 20px 0;
}

.gallery img {
    width: 200px;
    margin: 10px;
}

footer {
    background-color: #333;
    color: white;
    padding: 10px 0;
    text-align: center;
    position: absolute;
    width: 100%;
}