@media (max-width:991px) {
    body.poster {
        margin-top: 40vh;
    }
}

body.poster {
    background-attachment: fixed;
}

.poster:before {
    background-image: url(assets/images/IMG-0561.JPG) !important;
}

@media (min-width: 1440px), (min-width: 992px) and (-webkit-min-device-pixel-ratio: 2), (min-width: 992px) and (min-resolution: 192dpi) {
    .poster:before {
        background-image: url(assets/images/IMG-0561.JPG) !important;
    }
}

.back-to-top {
    position: fixed;
    background-image: none;
    right: 20px;
    bottom: 20px;
    display: block;
    opacity: 0.7;
}