How to slim down Ubuntu GNOME title bar fatness?

Question

Previously the title bars for windows were much thinner than they are now on Ubuntu GNOME 16.04.1 with GNOME 3.20. Why is this and how can I change this? I liked the slim look I got with the numix-gtk-theme, but for some reason I don't get that slim look any more. Not with any theme.

This is how fat it is:

Answer 1

You're seeing this fatter title bar because you're using Gnome-Shell. In Gnome-Shell, the title bars of Numix theme are much fatter than the versions for Unity.

Check these two images

1. Unity

   

2. Gnome Shell

   

To reduce the titlebar's fatness

To reduce this fatness, follow these steps

1. Create a file in ~/.config/gtk-3.0/gtk.css with these contents

.header-bar.default-decoration {
    padding-top: 4px;
    padding-bottom: 4px;
    }

.header-bar.default-decoration .button.titlebutton {
    padding-top: 4px;
    padding-bottom: 4px;
}

/* No line below the title bar */
.ssd .titlebar {
    border-width: 2px;
    box-shadow: none;
}

2. Log out and Login again.

   A screenshot from gnome-shell session after change

   

However, It's reported that this tweak doesn't work for GNOME 3.20 sometimes. To tackle that, you may need the solution from this question

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

^{Source: https://unix.stackexchange.com/questions/257163/reduce-title-bar-height-in-gnome-3-gtk-3}