message: feat(theme): improve sidebar style
diff: }
  &::-webkit-scrollbar {
  - width: 7px;
  + width: 6px;
  + height: 6px;
  }
  &::-webkit-scrollbar-track {
  - background-color: var(--border);
  + background-color: rgba(0, 0, 0, 0.1);
  + -webkit-border-radius: 6px;
  + border-radius: 6px;
  }
  &::-webkit-scrollbar-thumb {
  background-color: var(--accent-color);
  +
  + &:horizontal {
  + width: 6px;
  }
  + &:vertical {
  + height: 6px;
  + }
  + }
  @media (max-width: config.$pad) {
  width: var(--mobile-sidebar-width);
  font-size: 15px;
  