/* Mobile-first base styles */
body {
    margin: 0;
    font-family: 'Segoe UI', Arial, sans-serif;
    background: #f9f9f9;
    color: #222;
    line-height: 1.6;
}

header, nav, main, footer {
    padding: 1rem;
    margin: 0 auto;
    max-width: 1200px;
}

header {
    background: #0078d4;
    color: #fff;
    text-align: center;
}

nav {
    margin: 1rem 0;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

nav a {
    color: #0078d4;
    text-decoration: none;
    padding: 0.5rem;
    border-radius: 4px;
    transition: background 0.2s;
}

nav a:hover {
    background: #e5f1fb;
}

main {
    background: #fff;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.05);
    padding: 1.5rem;
}

footer {
    text-align: center;
    font-size: 0.9rem;
    color: #666;
    margin-top: 2rem;
}

/* Mobile: up to 599px (default styles already applied) */

/* Tablet: 600px to 1023px */
@media (min-width: 600px) and (max-width: 1023px) {
    nav {
        flex-direction: row;
        justify-content: center;
        gap: 1rem;
    }
    main {
        padding: 2rem 3rem;
    }
}

/* Desktop: 1024px and up */
@media (min-width: 1024px) {
    header, nav, main, footer {
        max-width: 1600px;
    }
    nav {
        flex-direction: row;
        justify-content: flex;
        gap: 2rem;
    }
    main {
        padding: 3rem 5rem;
    }
}