.jarallax {
    position: relative;
    background-size: cover;
    background-repeat: no-repeat;
    background-position: 50% 50%;
}
.jarallax {
    height: 600px;
}


/* hero block */
.demo-table {
    display: table;
    width: 100%;
    height: 600px;
    background-color: rgba(39,35,51,0.8);
}
.demo-table-cell {
    display: table-cell;
    text-align: center;
    vertical-align: middle;
}