[OBSOLETE stopped working with firefox 71]
The Tab Mix Plus addon stopped working with v57 :-(
- Open about:config and set toolkit.legacyUserProfileCustomizations.stylesheets to true.
- Open a new tab on about:support
- Click the button next to “Profile Folder”
- Go to the “chrome” directory at the profile folder, or create it if it doesn’t exist.
- Create a file named “userChrome.css” (if it doesn’t exist) and open it in a text editor.
- Copy the css code from github.com/andreicristianpetcu/UserChrome-Tweaks
(copy of the css is at the bottom of this post) - Paste it into userChrome.css and save.
- Restart Firefox
Update for v58: Changed .tabbrowser-tabs to #tabbrowser-tabs.
Update for v65: Removed #titlebar related stuff
userChrome.css
.tabbrowser-tab:not([pinned]) { flex-grow:1; min-width:150px; } .tabbrowser-tab,.tab-background { height:var(-tab-min-height); } .tab-stack { width: 100%; } #tabbrowser-tabs .scrollbox-innerbox { display: flex; flex-wrap: wrap; } #tabbrowser-tabs .arrowscrollbox-scrollbox { overflow: visible; display: block; } #tabbrowser-tabs .scrollbutton-up,#tabbrowser-tabs .scrollbutton-down,#alltabs-button,.tabbrowser-tab:not([fadein]){ display: none; } #main-window[sizemode="maximized"] #TabsToolbar{ margin-left:var(-tab-min-height); } /* #titlebar,#titlebar-buttonbox{ height:var(--tab-min-height) !important; } #titlebar{ margin-bottom:calc(var(--tab-min-height)*-1) !important; } #main-window[sizemode="maximized"] #titlebar{ margin-bottom:calc(6px + var(--tab-min-height)*-1) !important; } #titlebar:active{ margin-bottom:0 !important; } #titlebar:active #titlebar-content{ margin-bottom:var(--tab-min-height) !important; } */
Based on instructions here.