body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #ffffff; /* Set entire background to white */
    color: #333; /* Dark text color */
}

header {
    background: #ffffff; /* White background for header */
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1); /* Subtle shadow */
    padding: 2rem; /* Padding for desktop */
    text-align: center;
}

nav {
    width: 100%; /* Full width for the navigation */
}

nav ul {
    list-style: none;
    padding: 0;
    margin: 0; /* Remove default margin */
    display: flex; /* Use Flexbox for horizontal alignment */
    justify-content: space-around; /* Evenly space items */
}

nav ul li {
    flex: 1; /* Allow items to grow equally */
    text-align: center; /* Center text within each item */
}

nav ul li a {
    display: block; /* Make links block elements */
    padding: 1rem; /* Add padding for better click area */
    color: #0071e3; /* Apple blue color */
    text-decoration: none;
    font-weight: 500; /* Medium weight for links */
    background-color: #f0f0f0; /* Light gray background for buttons */
}

nav ul li a:hover {
    background-color: #e0e0e0; /* Slightly darker gray on hover */
    text-decoration: underline; /* Underline on hover */
}

nav ul li a.active {
    background-color: #ffffff; /* White background for the active page */
}

section {
    padding: 2.5rem 1rem; /* Use rem for responsive padding */
    margin: 2rem auto; /* Use rem for responsive margin */
    max-width: 90%; /* Use percentage for responsive width */
    background: #ffffff; /* White background for sections */
    border-radius: 0; /* No rounded corners */
    box-shadow: none; /* No shadow for sections */
}

footer {
    text-align: center;
    padding: 2rem; /* Use rem for responsive padding */
    background: #ffffff; /* White background for footer */
    color: #333;
    box-shadow: 0 -1px 3px rgba(0, 0, 0, 0.1); /* Subtle shadow */
}

h1, h2 {
    font-weight: 600; /* Bold headings */
}

h2 {
    color: #333; /* Dark text color for headings */
}

ul {
    list-style-type: disc;
    margin-left: 2rem; /* Use rem for responsive margin */
}

/* Media Queries for Mobile Responsiveness */
@media (max-width: 600px) {
    header {
        padding: 1rem; /* Reduced padding for mobile */
    }

    nav ul {
        flex-direction: column; /* Stack items vertically */
        align-items: stretch; /* Stretch items to full width */
    }

    nav ul li {
        width: 100%; /* Full width for each item */
    }

    nav ul li a {
        padding: 1rem; /* Maintain padding for touch targets */
        text-align: center; /* Center text */
    }

    section {
        padding: 1.5rem; /* Adjust padding for smaller screens */
        margin: 1rem auto; /* Adjust margin for smaller screens */
    }

    footer {
        padding: 1rem; /* Adjust footer padding */
    }

    h1 {
        font-size: 1.5rem; /* Adjust heading size for mobile */
    }

    h2 {
        font-size: 1.25rem; /* Adjust subheading size for mobile */
    }
}