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

body {
    font-family: Arial, sans-serif;
    line-height: 1.6;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

header {
    background: #333;
    color: white;
    padding: 1rem;
    text-align: center;
}

nav {
    background: #444;
    padding: 1rem;
}

nav ul {
    list-style: none;
    display: flex;
    justify-content: center;
    gap: 20px;
}

nav a {
    color: white;
    text-decoration: none;
    padding: 5px 10px;
}

.container {
    display: flex;
    flex: 1;
    padding: 20px;
    gap: 20px;
}

main {
    flex: 3;
}

aside {
    flex: 1;
    background: #f4f4f4;
    padding: 20px;
}

footer {
    background: #333;
    color: white;
    text-align: center;
    padding: 1rem;
    margin-top: auto;
}

@media (max-width: 768px) {
    .container {
        flex-direction: column;
    }

    nav ul {
        flex-direction: column;
        text-align: center;
        gap: 10px;
    }

    aside {
        order: -1;
    }
}

@media (max-width: 480px) {
    header h1 {
        font-size: 1.5rem;
    }

    nav {
        padding: 0.5rem;
    }
}