body {
    font-family: Arial, sans-serif;
    background-color: #f4f4f4;
    margin: 0;
}

#container {
    width: 90%;
    max-width: 1100px;
    margin: auto;
    background: white;
}

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

#nav {
    background: red;
    text-align: center;
    padding: 10px;
}

#nav a {
    color: white;
    margin: 10px;
    text-decoration: none;
}

#left-column {
    width: 60%;
    float: left;
    padding: 20px;
}

#right-column {
    width: 40%;
    float: left;
    padding: 20px;
    background: #eee;
}

.car-box {
    background: white;
    padding: 10px;
    margin-bottom: 10px;
}

#footer {
    clear: both;
    background: black;
    color: white;
    text-align: center;
    padding: 15px;
}

@media screen and (max-width: 768px) {
    #left-column, #right-column {
        width: 100%;
        float: none;
    }
}