How to change the titlebar height in standard GTK apps and those with headerbars/CSDs on Gnome 3.20

In Gnome 3.18, it was possible to change the titlebar height of all windows by changing the css in ~/.config/gtk-3.0/gtk.css as per https://unix.stackexchange.com/questions/257163/reduce-title-bar-height-in-gnome-3-gtk-3 . .header-bar.default-decoration { padding-top: 0px; padding-bottom: 0px; } .header-bar.default-decoration .button.titlebutton { padding-top: 0px; padding-bottom: 0px; } /* No line below the title bar */ .ssd .titlebar { border-width: 0; box-shadow: none; } In Gnome 3.20, this appears to no longer apply to windows with a headerbar/CSD (gnome-specific buttons in the title bar), such as Nautilus (Files), Settings, Photos, Contacts, etc. The tweak still reduces the titlebar height for other applications, such as gnome-terminal and gVim. How do I reduce the height of the titlebar in gnome-programs such as Nautilus in Gnome 3.20? --- ### Update I have also tried what is suggested in this reddit thread . I tried both window.ssd and .ssd only, no dice. _This works, see the answer I posted for more details_ window.ssd headerbar.titlebar { padding-top: 1px; padding-bottom: 1px; min-height: 0; } window.ssd headerbar.titlebar button.titlebutton { padding-top: 1px; padding-bottom: 1px; min-height: 0; } and /* shrink headebars */ headerbar { min-height: 38px; padding-left: 2px; /* same as childrens vertical margins for nicer proportions */ padding-right: 2px; } headerbar entry, headerbar spinbutton, headerbar button, headerbar separator { margin-top: 2px; /* same as headerbar side padding for nicer proportions */ margin-bottom: 2px; } /* shrink ssd titlebars */ .default-decoration { min-height: 0; /* let the entry and button drive the titlebar size */ padding: 2px } .default-decoration .titlebutton { min-height: 26px; /* tweak these two props to reduce button size */ min-width: 26px; }