Firefox userChrome for poweruser

userChrome.css

/*
This will hide search box/bar in Firefox
you should enable legacy customization too
While this will hide some elements you should use this HotKeys
	show search box: CTRL-L or ALT-D or F6
	hide search box: Esc | Tab
	go-back: ALT - <=
	go-forward: ALT- =>
	reload: CTRL-r
	switch tabs: ALT-(1-8)
	last tab:  ALT-9
*/

/* colors */
:root{
    --mff-bg: #292f36;
    --mff-search-box-bg: rgba(41,47,54,.97);
    --mff-tab-selected-bg:#e0fbfc14;
}

/* TABS */
#tabbrowser-arrowscrollbox{
    counter-reset: tabs;
}

.tab-background {
  border: none !important;
}

.tabbrowser-tab {
    margin-right: 3px !important;
}

.tabbrowser-tab::after,
.tabbrowser-tab::before {
  border-left: none !important;
}

.tabbrowser-tab::before {
    counter-increment: tabs;
    content: "#"counter(tabs);
    position: absolute;
    color: white;
    opacity: 1 !important;
    font-size: 8px;
    left: 3px;
}

.tab-background[selected="true"] {
    background: var(--mff-tab-selected-bg) !important;
}

.tab-background:not[visuallyselected] {
    background: var(--mff-tab-selected-bg) !important;
    opacity: 0.5 !important;
}


/* URL Bar */
hbox#urlbar-background{
    background: none !important;
}

hbox#urlbar[breakout], hbox#urlbar[breakout][breakout-extend] {
    position: fixed !important;
    top: 25% !important;
    width: 400px !important;
    height: auto !important;
    left: calc(50% - 200px) !important;
    background-color: var(--mff-search-box-bg) !important; 
    padding: 10px !important;
    border: 1px solid #fff !important;
    box-shadow: 1px 1px 4px #000000a3 !important;
    overflow: hidden !important;
}

#home-button, #back-button, #forward-button,
#reload-button, #stop-reload-button, #library-button,
#sidebar-button, #fxa-toolbar-menu-button,
.webextension-browser-action[data-extensionid],
#pocket-button,  .tab-close-button, .tab-line {
    display: none !important;
}

#navigator-toolbox{
    display: flex !important;
    background-color: var(--mff-bg) !important; 
    border-bottom: 0 !important;
}

#titlebar{
    flex-grow: 1 !important;
}

toolbaritem#urlbar-container{
    min-width: unset !important;
    margin: 0 !important;
}

toolbaritem#PanelUI-button{
    margin-inline: 0 !important;
    border-inline-start: 0 !important;
}


#TabsToolbar-customization-target{
    height: 40px !important;
}

toolbar#nav-bar{
    background: unset !important;
}

hbox#urlbar[breakout][breakout-extend] > #urlbar-input-container {
    padding: 0 !important;
    padding-block: 0 !important;
    padding-inline: 0 !important;
    height: auto !important;
}

.urlbarView-body-inner{
	border: none !important;
}

Nice script