message: Update _SpacePanel.scss
diff: @@ -147,6 +147,8 @@ $activeBorderColor: $secondary-fg-color;
  .mx_SpaceButton_toggleCollapse {
  width: $gutterSize;
  + // negative margin to place it correctly even with the complex
  + // 4px selection border each space button has when active
  margin-right: -4px;
  height: 20px;
  mask-position: center;
  