message: fix(panel): normal scrollbar width on firefox
diff: $scrollbar-size: 8px;
  -$scrollbar-ff-width: thin; // FF-only accepts auto, thin, none
  +$scrollbar-ff-width: auto; // FF-only accepts auto, thin, none
  $scrollbar-minlength: 50px; // Minimum length of scrollbar thumb
  $scrollbar-track-color: transparent;
  $scrollbar-color: rgba(138, 138, 138, 0.25);
  