GTK 3 Adwaita tabs are too high

xfce4-terminal is now using GTK 3 in Debian Stretch which gives me tabs looking like:

I thinks this is too high for my 768 pixels laptop screen. Fortunately Gtk 3 themes are CSS based and can be easily tweaked. Adding:

notebook tab {
    padding: 0px;
    font-weight: normal;

to the ~/.config/gtk-3.0/gtk.css file will change all GtkNodebook widgets so they look like:

An easy way to test more CSS rules is using GtkInspector.

This is fixed in xfce4-terminal 0.8.4: