* {
    box-sizing: border-box;
}

body {
    /*max-width:1000px;
    margin: auto;
    border: 3px solid #73AD21;
    */
    font-family: Arial;
    padding: 10px;
    background: #f1f1f1;
}

/* Header/Blog Title */
.header {
    padding: 30px;
    text-align: center;
    background: white;
}

.header h1 {
    font-size: 50px;
}

/* 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;
}

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

/* Create two unequal columns that floats next to each other */
/* Left column */
.leftcolumn {
    float: left;
    width: 20%;
}

/* middle column */
.rightcolumn {
    float: right;
    width: 80%;
    background-color: #f1f1f1;
    padding-left: 20px;
}

/* middle column */
.ad_bar {
    background-color: #f1f1f1;
    position: fixed;
    width: 100%;
    bottom: 0;
    right: 0;
    padding-top: 20px;
    text-align: center;
}


/* Add a card effect for articles */
.card {
    background-color: white;
    padding: 20px;
    margin-top: 20px;
}

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

/* Footer */
.footer {
    padding: 20px;
    text-align: center;
    background: #ddd;
    margin-top: 20px;
}

.sticky_toc {
    position: fixed;
    top: 0;
    width: 20%;
}

/* Responsive layout - when the screen is less than 800px wide, make the two columns stack on top of each other instead of next to each other */
@media screen and (max-width: 1000px) {
    .leftcolumn, .rightcolumn {   
        width: 100%;
        padding: 0;
    }
    .sticky_toc {   
        width: 100%;
        position: relative;
    }
    .ad_bar {   
        width: 100%;
    }
}