body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    line-height: 1.6;
}

header {
    background: #333;
    color: #fff;
    padding: 1rem 0;
    text-align: center;
}

nav {
    background: #444;
    display: flex;
    justify-content: center;
    gap: 1rem;
    padding: 0.5rem 0;
}

nav a {
    color: #fff;
    text-decoration: none;
}

nav a:hover {
    text-decoration: underline;
}

.container {
    display: flex;
    flex-wrap: wrap;
    padding: 1rem;
}

aside {
    flex: 1 1 20%;
    background: #f4f4f4;
    padding: 1rem;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

main {
    flex: 1 1 60%;
    padding: 1rem;
}

article {
    margin-bottom: 1.5rem;
}

footer {
    background: #333;
    color: #fff;
    text-align: center;
    padding: 1rem 0;
    margin-top: 2rem;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin: 1rem 0;
}

table, th, td {
    border: 1px solid #ddd;
}

th, td {
    padding: 0.5rem;
    text-align: left;
}

form {
    margin: 1rem 0;
}

form input, form textarea, form button {
    display: block;
    width: 100%;
    margin: 0.5rem 0;
    padding: 0.5rem;
}

@media (max-width: 768px) {
    aside {
        flex: 1 1 100%;
        margin-bottom: 1rem;
    }

    main {
        flex: 1 1 100%;
    }
}