body, html {
    height: 50%;
    margin: 0;
    font-family: Arial, Helvetica, sans-serif;
    color: black;
}

.topnav {
    overflow: hidden;
    background-color: #333;
}

.topnav a {
        float: left;
        color: #f2f2f2;
        text-align: center;
        padding: 14px 16px;
        text-decoration: none;
        font-size: 17px;
}

.topnav a:hover {
        background-color: #ddd;
        color: black;
}

.topnav a.active {
        background-color: #4CAF50;
        color: white;
}

img {
    width: 100%;
}

table {
    font-family: arial, sans-serif;
    border-collapse: collapse;
    table-layout: fixed;
    width: 85%;
    text-align: left;
    column-width:inherit;
}

td, th {
    position: center;
    border: 0px solid #dddddd;
    text-align: left;
    padding: 8px;
    height: 70%;
    width:80%;
    background-position: center;
    background-repeat: no-repeat;
    background-size: cover;
    position: center;
}