Как поменять направление скролла?

(function() {


  let scroll = document.querySelector('.scroll-block');

  let left = 0;
  let drag = false;
  let coorX = 0;

  scroll.addEventListener('mousedown', function(e) {
    drag = true;
    coorX = e.pageX - this.offsetLeft;
  });
  document.addEventListener('mouseup', function() {
    drag = false;
    left = scroll.scrollLeft;
  });
  scroll.addEventListener('mousemove', function(e) {
    if (drag) {
      this.scrollLeft = left + (e.pageX - this.offsetLeft - coorX);
    }
  });


})();

.scroll-block {
  position: relative;
  overflow-x: auto;
  overflow-y: hidden;
  height: 200px;
  white-space: nowrap;
  scrollbar-width: none;
  -ms-overflow-style: none;

}

.scroll-block::-webkit-scrollbar {
  width: 0px;
  background: transparent;
}

.block {
  display: inline-block;
  height: 100%;
  width: 80vw;
  background-color: orange;
  border-right: 3px solid #045acf;
  -webkit-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  user-select: none;
}

 <div class="scroll-block">
      <div class="block">БЛОК1</div>
      <div class="block">БЛОК2</div>
      <div class="block">БЛОК3</div>
      <div class="block">БЛОК4</div>
      <div class="block">БЛОК5</div>
    </div>