body {
    background-color: black;
}

ul {
    list-style-type: none;
    background-color: black;
}

li a {
    float: left;
    display: block;
    font-family: 'Courier New', Courier, monospace;
    color: whitesmoke;
    text-decoration: none;
    margin: auto;
    padding: 10px;
}

.active {
    color: yellow;
}

li a:hover {
    background-color: whitesmoke;
    color: black;

}

.header {
    font-family: 'Courier New', Courier, monospace;
    color: whitesmoke;
    text-align: center;
    padding: 20px;
}

/* The navigation bar on top of the page */
.topnav {
    overflow: hidden;
    background-color: black;
}

/* Navigation bar links */
.topnav a {
    float: left;
    display: block;
    font-family: 'Courier New', Courier, monospace;
    color: whitesmoke;
    text-align: center;
    padding: 14px 16px;
    text-decoration: none;
}

/* Links - change the hover color */
.topnav a:hover {
    background-color: white;
    color: black;
}

/* Create 3 columns of the same size */
.column {
    float: left;
    width: 33.33%;
    background-color: black;
    font-family: 'Courier New', Courier, monospace;
    color: whitesmoke;
}

/* Clear floats after the columns */
.row:after {
    content: "";
    display: table;
    clear: both;
}

/* Responsive layout - makes the columns stack on top of each other if the website is viewed on a smaller screen,
    for example, on a smart phone */
@media screen and (max-width: 600px) {
    .column {
        width: 100%;
    }
}