Make GNOME 3.30 Look Great Again

I have updated the CSS snippet from my post last year to be compatible to GNOME 3.30, as e.g. used in Debian Buster:

.default-decoration.titlebar:not(headerbar), headerbar.default-decoration {
  padding: 0 6px;
  min-height: 46px;
  border: none;
  background-image: linear-gradient(to bottom,
  shade(@theme_bg_color, 1.05),
  shade(@theme_bg_color, 0.99));
  box-shadow: inset 0 1px shade(@theme_bg_color, 1.4);
.default-decoration .titlebutton {
  min-height: 24px;
  min-width: 16px;
  padding: 4px 9px;

Again, this changes the appearance of title bars to avoid their “spare part” look on some applications (Firefox, LibreOffice, Terminal).