message: disable selection for post add button placeholder message
diff: @@ -36,6 +36,8 @@ $-height = 40px
  position: relative
  height: $-height
  line-height: $-height
  + user-select: none
  + -moz-user-select: none
  &::before
  caret(var(--theme-bg-subtle), size: 9px)
  