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

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

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

nav ul li {
    position: relative;
}

nav ul li a {
    display: block;
    color: white;
    padding: 14px 20px;
    text-decoration: none;
}

nav ul li a:hover, .dropdown:hover .dropbtn {
    background-color: #111;
}

.dropdown-content {
    display: none;
    position: absolute;
    background-color: #444;
    min-width: 160px;
    box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
    z-index: 1;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.dropdown-content a {
    color: white;
    padding: 12px 16px;
    text-decoration: none;
    display: block;
}

.dropdown-content a:hover {
    background-color: #555;
}

.dropdown:hover .dropdown-content {
    display: block;
    opacity: 1;
}