#page-div
{
    position: relative;
    min-height: 100vh;
}

#main-div 
{
    padding-bottom: 5rem;    /* Footer height */
}

#footer 
{
    position: absolute;
    bottom: 0;
    width: 100%;
    height: 5rem;            /* Footer height */
}

.popup-btn-right button
{
    top: 46%;
    position: fixed;
    right: 20px;
    z-index: 1000;
    padding: 10px 15px;
}

.popup-btn-left button
{
    top: 46%;
    position: fixed;
    left: 20px;
    z-index: 1000;
    padding: 10px 15px;
}