body {
    background-color: #99cc99;
    font-family: sans-serif;
    font-size: 100%;
}

.header {
    background-color: aliceblue;
    padding: 20px;
    text-align: center;
    font-size: 2.5em;
}

/* Style the top navigation bar */
.topnav {
    overflow: hidden;
    background-color: #333;
}

/* Style the topnav links */
.topnav a {
    float: left;
    display: block;
    color: #f2f2f2;
    text-align: center;
    padding: 14px 16px;
    text-decoration: none;
    font-size: 1em;
}

/* Change color on hover */
.topnav a:hover {
    background-color: #ddd;
    color: black;
}

/* Create three unequal columns that floats next to each other */
.column {
    float: left;
    background-color: white;
    margin: 5px;
    text-align: center;
}

/* Left and right column */
.column.side {
    width: 20%;
}

/* Middle column */
.column.middle {
    width: 57%;
}

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

@media screen and (max-device-width: 500px) {
    img {
        max-width: 95%;
        height: auto;
    }

    .topnav a {
        font-size: 3vw;
    }

    .header {
        font-size: 5vw;
    }

    .column.side,
    .column.middle {
        width: 100%;
    }
}