body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    margin: 0;
    padding: 0;
    color: #333;
    background-color: #f5f5f7;
}

header {
    background-color: #fff;
    padding: 20px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

nav ul {
    list-style: none;
    padding: 0;
}

nav ul li {
    display: inline;
    margin-right: 20px;
}

nav ul li a {
    text-decoration: none;
    color: #007aff;
}

main {
    padding: 20px;
}

section {
    margin-bottom: 40px;
}

footer {
    text-align: center;
    padding: 10px;
    background-color: #fff;
    box-shadow: 0 -2px 4px rgba(0, 0, 0, 0.1);
}