.container {
    display: flex;
    flex-direction: row;
}

.nav-column {
    background-color: #333;
    color: #fff;
    padding: 1em;
    width: 200px;
}

.nav-column ul {
    list-style: none;
    margin: 0;
    padding: 0;
}

.nav-column li {
    margin-bottom: 10px;
}

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

.content-column {
    flex: 1;
    padding: 1em;
}

header {
    background-color: #333;
    color: #fff;
    padding: 1em;
    text-align: center;
    margin-bottom: 10px;
}

footer {
    background-color: #333;
    color: #fff;
    padding: 1em;
    text-align: center;
    clear: both;
}