message: fix unclickable space
diff: left: 0;
  bottom: 0;
  width: 30px;
  - height: 30px;
  @media (max-width: 768px) {
  display: none;
  div {
  box-sizing: border-box;
  width: 14px;
  - height: 100%;
  + height: 30px;
  background-color: $windowListSB_bg;
  color: $windowListSB_color;
  text-align: center;
  