.go_to_prev,
.go_to_next {
    float: left;
    width: 40px;
    height: 40px;
    top: calc(50% - 20px);
    position: fixed;
    opacity: 0.7;
    cursor: pointer;
    z-index: 9999;
    display: block;
    background: url('../../images/arrow.png') no-repeat center center / cover;
}
.go_to_prev:hover,
.go_to_next:hover {
    opacity: 1;
}
.go_to_next {
    right: 20px;
    transform: rotate(90deg);
}
.go_to_prev {
    left: 20px;
    transform: rotate(-90deg);
}