message: Tweak the alignment of the tab close button.
diff: @@ -140,6 +140,7 @@ DIV.tab_header_container:hover > DIV.tab_header_close > BUTTON > I {
  DIV.tab_header_close > BUTTON.microtool.danger {
  background-image: none;
  + vertical-align: -0.2rem;
  &:hover {
  color: $tab-background-color;
  