userChrome.css

/* Example userChrome.css file */

/* Import your desired components first */

/* @import url(chrome/tab_close_button_always_on_hover.css); */
/* @import url(chrome/tab_loading_progress_throbber.css); */

@import url(chrome/autohide_bookmarks_and_main_toolbars.css);

/*@import url(chrome/hide_tabs_toolbar_v2.css);*/
@import url(button_effect_scale_onhover.css);

/* Apply your custom modifications after imports */
/**
 * Hide sidebar-panel-header (sidebar.revamp: true)
 */
#sidebar-panel-header {
display: none;
}

/**
 * Dynamic styles
 *
 * Choose when styles below will be activated (comment/uncomment line)
 * - When Sidebery set title preface "."
 * - When Sidebery sidebar is active
 */

/* #main-window:has(#sidebar-box[sidebarcommand="_3c078156-979c-498b-8990-85f7987dd929_-sidebar-action"][checked="true"]) { */

/* Hide horizontal native tabs toolbar */
#TabsToolbar {
display: none !important;
}

/* Hide top window border */
/* #nav-bar {
border-color: transparent !important;
} */

/* Hide new Firefox sidebar, restyle addon's sidebar */
#sidebar-main, #sidebar-launcher-splitter {
display: none !important;
}
#sidebar-box {
padding: 0 !important;
}
#sidebar-box #sidebar {
box-shadow: none !important;
border: none !important;
outline: none !important;
border-radius: 0 !important;
}
#sidebar-splitter {
--splitter-width: 3px !important;
min-width: var(--splitter-width) !important;
width: var(--splitter-width) !important;
padding: 0 !important;
margin: 0 calc(-1*var(--splitter-width) + 1px) 0 0 !important;
border: 0 !important;
opacity: 0 !important;
}

/* Update background color of the #browser area (it's visible near the
 * rounded corner of the web page) so it blends with sidebery color with
 * vertical nav-bar. */
#browser {
background-color: var(--lwt-accent-color) !important;
background-image: none !important;
}

/* Hide sidebar header (sidebar.revamp: false) */
 #sidebar-header {
 display: none !important;
}