* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: Arial, sans-serif;
    line-height: 1.6;
    background-color: #f4f4f4;
    color: #333;
    padding: 10px;
}

header {
    background: #2c3e50;
    color: white;
    padding: 15px;
    text-align: center;
}

nav ul {
    list-style: none;
    margin-top: 10px;
}

nav ul li {
    margin: 8px 0;
}

nav ul li a {
    color: white;
    text-decoration: none;
    font-weight: bold;
}

.content {
    background: white;
    padding: 20px;
    margin-top: 15px;
    border-radius: 5px;
}

footer {
    margin-top: 20px;
    text-align: center;
    padding: 10px;
    background: #ddd;
}

/* ===== Tablet (≥768px) ===== */
@media (min-width: 768px) {
    
    body {
        padding: 20px;
    }

    nav ul {
        display: flex;
        justify-content: center;
    }

    nav ul li {
        margin: 0 15px;
    }

    .content {
        max-width: 700px;
        margin: 20px auto;
    }
}

/* ===== Desktop (≥1024px) ===== */
@media (min-width: 1024px) {

    body {
        max-width: 1200px;
        margin: 0 auto;
    }

    header {
        padding: 25px;
    }

    .content {
        max-width: 900px;
        font-size: 1.1rem;
    }

    nav ul li a:hover {
        color: #3498db;
    }
}