WIP dark theme for Firefox 57+ (Quantum)

userChrome.css

scrollbar,
scrollbar scrollbarbutton,
scrollbar slider,
scrollbar thumb {
    -moz-appearance: none;
}

scrollbar scrollbarbutton {
    visibility: collapse;
}

scrollbar,
scrollbar slider{
    min-width: 12px;
}

scrollbar thumb {
    background-color: #ccc3;
    border-radius: 100px;
    box-shadow: 0 0 0 1px #fff1 inset;
}

scrollbar[orient="vertical"] thumb {
    min-width: 0;
    min-height: 50px;
}

scrollbar[orient="horizontal"] thumb {
    min-width: 50px;
    min-height: 0;
}




#TabsToolbar {
    visibility: collapse;
}

#titlebar {
    margin-bottom: -34px !important;
}

#titlebar-buttonbox {
    height: 32px !important;
}

#nav-bar {
    margin-right: 180px;
}

#main-window[sizemode="maximized"] #nav-bar {
    margin-right: 138px;
}


#sidebar-box {
    background-color: #333 !important;
}


#sidebar-header {
    border-color: #454545 !important;
}

.tree-stack { 
    /*probably need fix*/
    /*color: #ccc !important;*/
}

#sidebar-splitter {
    border-color: #393939 !important;
}

#sidebar-switcher-target {
    color: #ccc !important;
}

.panel-arrow[side="top"],
.panel-arrow[side="bottom"] {
    filter: invert(80%);
}


.panel-arrowcontent {
    --arrowpanel-background: #333;
    --arrowpanel-color: #ccc;
}

photonpanelmultiview .PanelUI-subView .toolbaritem-combined-buttons > .subviewbutton:not(.subviewbutton-iconic) {
    background-color: #333;
    border: 1px solid #454545;
}

toolbarbutton[checked="true"]:not([disabled="true"]) {
    color: #fff !important;    
}

#customizationui-widget-panel toolbarbutton[checked="true"] .toolbarbutton-icon {
    filter: invert(100%);
}

photonpanelmultiview .PanelUI-subView .toolbaritem-combined-buttons > .subviewbutton:not(.subviewbutton-iconic) {
    background-color: #fff2 !important;
    border-color: #fff4 !important;
}


treechildren::-moz-tree-row(hover) {
    color: #fff !important;
}

.sidebar-placesTreechildren{
    color: #ccc;
    background-image: none;
    background-color: transparent;
}

.sidebar-placesTreechildren::-moz-tree-row(hover) {
    color: #000 !important;
    background-image: none !important;
    background-color: #fff2 !important;
}