That one cool 4chan person's FF CSS

    @namespace url(http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul);

    /*remove blue browser border */
    #main-window:not([chromehidden*="toolbar"])[sizemode="normal"] {

     margin-top:-1px!important;

     margin-left:-1px!important;

     margin-right:-1px!important;

     margin-bottom: 33px !important;

    }

    /*Tabs */


    #TabsToolbar .tabbrowser-tabs:not([drag=detach]) > .tabbrowser-tab:not([pinned])[fadein] {

    min-width: 10px !important;

    max-width: 100% !important;

    }

    #TabsToolbar {

        margin-left: -15px !important;

        margin-right: -15px !important;
    }

    #TabsToolbar .tabbrowser-tab {

       text-align: center!important;

            -moz-border-top-colors: none !important;

            -moz-border-left-colors: none !important;

            -moz-border-right-colors: none !important;

            -moz-border-bottom-colors: none !important;

        background-color: #323636!important;

        color: #575757 !important;

        border-radius: 0px 0px 0px 0px !important;

        min-height: 33px !important;


    }


    #TabsToolbar .tabbrowser-tab[selected]  {

        background-color: #323636!important;

        color: #ffffff !important;

        border-radius: 0px 0px 0px 0px !important;

    }

    #TabsToolbar .tabbrowser-tab:hover:not([selected]) {

        background-color: #88a1ba!important;

        color: #ffffff !important;

    }

    #TabsToolbar .tab-background {

        margin: 0 !important;

        background: transparent !important;

    }

    .tabbrowser-tab:not([pinned]) .tab-icon-image{

        display: none !important;

    }

    #identity-box, #identity-icon-labels {

        display: none;
    }


    /* Australis Tabs */

    #TabsToolbar .tab-background {

        margin: 0 !important;

        background: transparent !important;

    }

    #TabsToolbar .tab-background-start,
    #TabsToolbar .tab-background-end {

        display: none !important;

    }

    #TabsToolbar .tab-background-middle {

        margin: 0px 0px !important;

        background: transparent !important;
    }

    #TabsToolbar .tabbrowser-tab:after,
    #TabsToolbar .tabbrowser-tab:before {

        display: none !important;

    }




    /* Navbar */

    #TabsToolbar:not([collapsed="true"]) + #nav-bar {

     border: 0px !important;

    }

    #navigator-toolbox > toolbar:not(:-moz-lwtheme):not(#toolbar-menubar):not(#TabsToolbar) {

            background: #323636 !important;

    }

    #nav-bar {

            background: #323636 !important;

            border: 0px #282B34!important;

            box-shadow: none !important;

      height: 33px !important;

      position: fixed !important;

      bottom: 0 !important;

      width: 100% !important;


    }



    #urlbar {

        background-color: #323636 !important;

        color: #575757!important;

        text-align: center !important;

        border-radius: 0px !important;

        border: none !important;

        margin: 0 0 0 0 !important;

        height: 33px !important;

        width: 2000px !important;

        padding-bottom: 5px !important;

        padding-left: 20px;

    }

    .findbar-container {

        background-color: #323636 !important;

        color: #575757!important;

    }

    .browserContainer > findbar {

        background-color: #323636 !important;

        color: #575757!important;

        text-shadow: none;

        border: 0px !important;

        padding-bottom: 30px !important;

    }

    .findbar-textbox {

        background-color: #323636 !important;

        color: #575757!important;

        border: 0px !important;


    }

    #editor-tools {

         background-color: #323636 !important;

         color: #fcfcfc!important;

    }


    .devtools-toolbarbutton  {

        color: #fcfcfc!important;

    }

    .main-content
     {

         background-color: #323636 !important;

         color: #fcfcfc!important;

    }

    .addon[selected]{

         background-color: #88a1ba !important;

         color: #fcfcfc !important;
    }

    #header-search{

         background-color: #323636 !important;

         color: #fcfcfc!important;

         border: 0px !important;

    }

    .header-button{

         background-color: #323636 !important;

         color: #fcfcfc!important;

         border: 0px !important;
    }

    button{

         background-color: #323636 !important;

         color: #fcfcfc!important;

         border: 0px !important;
    }

    button:hover
    {     background-color: #88a1ba !important;

         color: #fcfcfc !important;}

    /* buttons */

     #urlbar-reload-button, dropmarker,#back-button,#forward-button {

        display: none !important;

    }

    #back-button[disabled="true"]{

        display: none;

    }

    #forward-button[disabled="true"]{

       display: none;

    }



    #PanelUI-button {

        background-position: 100% 0, calc(100% - 1px) 0, calc(100% - 2px) 0;

        background: url('http://i.imgur.com/TkuW5hs.png') !important;

        background-repeat: no-repeat !important;

        background-position: center !important;

        box-shadow: none !important;

        width: 5px !important;

        border: 0px !important;

      }

    #PanelUI-menu-button {

        opacity: 0 !important;

        width: 10px !important;

        margin-right: -15px !important;

    }

    .tabbrowser-tab .tab-close-button {

            visibility: hidden !important;

            margin-left: -16px !important;

    }


    .tabbrowser-tab:hover .tab-close-button {

            visibility: visible !important;

            margin-left: 0px !important;

    }





    .tabs-newtab-button {

      background: transparent !important;

     list-style-image: url("http://a.pomf.cat/tilhhe.png") !important;

    -moz-image-region: auto !important;

    }




    scrollbox{

         background-color: #323636 !important;

    }



    /* fonts */

    #urlbar, #TabsToolbar .tabbrowser-tab, menu, .autocomplete-richlistbox, #menubar-items, statuspanel[type="overLink"] .statuspanel-label, toolbarbutton, #placeContent, #placesList, .editBMPanel_rowLabel, .textbox-input-box, .viewer-title.label.toolbar, .downloadTarget, .downloadDetails, #bookmarks-view-children, #sidebar-search-label, #sidebar-title, .menubar-text {

        font-family: 'sans'!important;

        font-size: 12px !important;

        text-shadow: none !important;

        font-weight: normal !important

    }


    /*Removes Separator*/

    #browser-bottombox {

            border: none !important;

    }



    #browser-border-end, #browser-border-start {

            display: none !important;

    }



    #nav-bar {

            border: none !important;

            visibility: visible !important;

    }



    #navigator-toolbox:after {

            height: 0px !important;

    }