#titles {text-align:center;}
#subtitle {font-size:x-large;}
img {margin-top:2em;}

   <style>
    body {font-family: "Lato", sans-serif;}

ul.tab {
    list-style-type: none;
    margin: 0;
    padding: 0;
    overflow: hidden;
    border: 1px solid #ccc;
    background-color: #f1f1f1;
}

/* Float the list items side by side */
ul.tab li {float: left;}

/* Style the links inside the list items */
ul.tab li a {
    display: inline-block;
    color: black;
    text-align: center;
    padding: 14px 16px;
    text-decoration: none;
    transition: 0.3s;
    font-size: 20px;
}

/* Change background color of links on hover */
ul.tab li a:hover {background-color: #ddd;}

/* Create an active/current tablink class */
ul.tab li a:focus, .active {background-color: #ccc;}
/* Style the tab content */
.tabcontent {
    display: none;
    padding: 6px 12px;
    border: 1px solid #ccc;
    border-top: none;
}
</style>
body {padding:1ex 1em 1ex 1em; }
p {max-width:55em;}

#jan1 {background-image: url(/plaatje.png);padding: 10px; color: white}
nav {width: 150px; padding-top: 15px; nbackground-color: khaki}