.header {
    background-color: #fff;
    text-align: center;
    padding: 30px;
}

/* The navbar container */
.topnav {
    overflow: hidden;
    background-color: #fff;
}

/* Navbar links */
.topnav a {
    float: left;
    display: block;
    color: #f2f2f2;
    text-align: center;
    padding: 14px 16px;
    text-decoration: none;
}

/* Create three equal columns that floats next to each other */
.column {
    float: left;
    width: 100%;
    padding: 15px;
    background-color: #fff
}

img {
    display: block;
    margin-left: auto;
    margin-right: auto;
}