If tab bar move to bottom screen (use userChrome.css) and
@-moz-document url("chrome://browser/content/browser.xhtml") {
:root:not([inFullscreen]) #browser { margin-bottom: 28px; }
:root:not([inFullscreen]) #TabsToolbar { position: fixed; display: flex; bottom: 0px; width: 100%; }
#tabbrowser-tabs { flex-grow: 1; }
#tabbrowser-tabs > .tabbrowser-arrowscrollbox { width: -moz-available }
#TabsToolbar-customization-target { width: 100%; }
.toolbar-items { width: 100%; }
}
addons dont work.