Tab horizontal scrollbar

/* .tabbrowser-tab[fadein]:not([pinned]) {
min-width: 100px !important;
} */

/*#TabsToolbar {
  overflow: auto !important;
}*/

tabs .tabbrowser-arrowscrollbox > scrollbox {
    overflow-x: auto;
    margin-bottom: -3px;
    padding-bottom: 3px !important;
}

tabs .tabbrowser-arrowscrollbox > scrollbox > scrollbar {
    -moz-appearance: none !important;
    min-height: 2px !important;
    max-height: 2px !important;
}

tabs .tabbrowser-arrowscrollbox > scrollbox > scrollbar > slider {
    min-height: 2px !important;
    max-height: 2px !important;
    background: #dfdfdf !important;
}

tabs .tabbrowser-arrowscrollbox > scrollbox > scrollbar > scrollbarbutton {
    display: none !important;
}

tabs .tabbrowser-arrowscrollbox > scrollbox > scrollbar > slider > thumb {
    -moz-appearance: none !important;
    border: none !important;
    background: threedshadow !important;
    min-height: 2px !important;
    max-height: 2px !important;
/*    border: none !important;
    background: #ff0000 !important; */
}