body {
    font-family: 'Arial', sans-serif;
    background-color: #f2f2f2;
    margin: 0;
    padding: 0;
}

#container {
    max-width: 1100px;
    margin: 40px auto;
    border: 1px solid #ddd;
    border-radius: 10px;
    background-color: #ffffff;
    box-shadow: 0 0 15px rgba(0, 0, 0, 0.1);
}

header {
    background-color: #17a2b8;
    color: white;
    padding: 20px;
    text-align: center;
}

#content {
    display: flex;
}

main {
    flex: 3;
    padding: 20px;
}

aside {
    flex: 1;
    background-color: #e9ecef;
    padding: 20px;
    margin-left: 20px;
    border-radius: 5px;
}

footer {
    background-color: #6c757d;
    color: white;
    text-align: center;
    padding: 15px;
}