body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #ffffff;
}

header, footer {
    background-color: #f5f5f5;
    text-align: center;
    padding: 20px;
}

nav ul {
    list-style-type: none;
    margin: 0;
    padding: 0;
    overflow: hidden;
    background-color: #333;
    display: flex;
    justify-content: center;
}

nav li {
    margin: 0 15px;
}

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

nav a:hover {
    background-color: #575757;
}

nav a.active {
    background-color: #575757;
}

main {
    padding: 20px;
    text-align: center;
}

h1, h2 {
    color: #333;
}

p {
    color: #555;
    font-size: 18px;
}

footer p {
    font-size: 14px;
    color: #777;
}

/* Responsive Design */
@media (max-width: 600px) {
    nav ul {
        flex-direction: column;
    }

    nav li {
        margin: 0;
    }

    nav a {
        padding: 10px;
    }
}