* {
    box-sizing: border-box;
}

body {
    font-family: Arial, Helvetica, sans-serif;
}

header {
    background-color: #999;
    padding: 10px;
    font-size: 15px;
    text-align: center;
    color: white;
}

table {
    width: 100%;
}

img left {
    float: left;
    display: block;
}

img center {
    display: block;
    margin: auto;
}

img right {
    float: right;
    display: block;
}

td side {
    width: 15%;
}

td center {
    text-align: center;
    width: 70%;
}

/* Create two columns/boxes that float next to each other */
nav {
    float: left;
    width: 15%;
    background-color: white;
    padding: 20px;
}

/* Style the list inside the menu */
nav ul {
    list-style-type: none;
    margin: 0;
    padding: 0;
    background-color: white;
    border: 1px solid #555;
    position: fixed; /* Make it stick, even on scroll */
    overflow: auto; /* Enable scrolling if the sidenav has too much content */
}

nav li a {
    display: block;
    color: #000;
    padding: 8px 16px;
    text-decoration: none;
}

nav li {
    text-align: center;
    border-bottom: 1px solid #555;
}

nav li:last-child {
    border-bottom: none;
}

nav li a.active {
    background-color: #6c8;
    color: white;
}

nav li a:hover:not(.active) {
    background-color: #555;
    color: white;
}

article {
    float: left;
    padding: 20px;
    width: 80%;
    background-color: #fff;
    height: 450px;
    overflow: scroll;
}

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

footer {
    background-color: #ff8;
    padding: 10px;
    text-align: center;
    color: #02f;
}