@namespace url("https://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"); /* only needed once */

/* Tab bar: adjust height - chrome://browser/skin/browser.css */
#tabbrowser-tabs,
.tab-background-start[selected=true]::after,
.tab-background-start[selected=true]::before,
.tab-background-start,
.tab-background-end,
.tab-background-end[selected=true]::after,
.tab-background-end[selected=true]::before {
  min-height: 18px!important;
}
#tabbrowser-tabs {height:18px!important;}
#tabbrowser-tabs toolbar button > .toolbarbutton-icon { padding-bottom:2px !important; }

.tab-text {padding-bottom:3px !important; }
.tab-throbber, .tab-icon-image  {padding-left:2px !important; }

Hi all, Thanks for your attention. I am using the last version of Mozilla Firefox on Windows 7. I want to reduce the height of the title bar and tabs bar, in order to save a much space as possible. Now, my title-bar and tabs-bar look like in the attached picture (default height, default theme). I want to kill all that blue space in terms of height. I'd like the blue region (I guess is the tabs-bar) to be as tall as a classic Windows Explorer title bar, which is 18 pixels (picture attached). Then, I'd like the grey area below (containing the address bar, the icons of Home, Add-ons, Bookmarks and so on and so forth) to be reduced too, to a height that is the minimum required to host the address bar, or maybe just 1 or 2 pixels more than that. If necessary, I would reduce all icons too, to fit in it. I want to do it manually (no external add-ons). I have already created chrome folder within the active profile folder and user.Chrome.css file (plain text, .css, UTF-8). I have tried a number of code lines to customize the tab height, read here and there around this and external websites, but still it does not work. It seems that Firefox ignores the .css file. To be accurate, if I increase the height, it works, if I decrease, it does not, like if there is a minimum threshold. I currently have the following text in my .css file (my last trial): <pre><nowiki>@namespace url("https://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"); /* only needed once */ /* Tab bar: adjust height - chrome://browser/skin/browser.css */ #tabbrowser-tabs, .tab-background-start[selected=true]::after, .tab-background-start[selected=true]::before, .tab-background-start, .tab-background-end, .tab-background-end[selected=true]::after, .tab-background-end[selected=true]::before { min-height: 18px!important; } #tabbrowser-tabs {height:18px!important;} #tabbrowser-tabs toolbar button > .toolbarbutton-icon { padding-bottom:2px !important; } </nowiki></pre> For the icon and the text you can modify the padding or margin of those elements with these selectors: <pre><nowiki>.tab-text {padding-bottom:3px !important; } .tab-throbber, .tab-icon-image {padding-left:2px !important; }</nowiki></pre> Can you help me to reach my target? User157954