.viewport {
  position: relative;
  overflow: hidden;
  /* Force the scrollbar into LTR mode so it is reliably aligned to the left. */
  direction: ltr;
}

/* scrollable is in LTR mode even if the body is in RTL mode. */
.scrollable {
  position: absolute;
  top: 0;
  /* @noflip */ right: 0;
  height: 100%;
  width: 100px;
  overflow-y: scroll;
  overflow-x: hidden;
}