gtk.css

@import "colors.css";
window.ssd separator:first-child + header:backdrop,
window.ssd separator:first-child + headerbar,
window.ssd headerbar:first-child:backdrop,
window.ssd headerbar:first-child,
window.ssd headerbar:last-child:backdrop,
window.ssd headerbar:last-child,
window.ssd stack headerbar:first-child:backdrop,
window.ssd stack headerbar:first-child,
window.ssd stack headerbar:last-child:backdrop,
window.ssd stack headerbar:last-child,
window.ssd decoration,
window.ssd headerbar.titlebar {
  border-radius: 0;
}

window.ssd headerbar * {
  margin-top: -100px;
  color: #1c2022; /* May need to tweak, this matches Adwaita Dark */
}

window.ssd headerbar.titlebar,
window.ssd headerbar.titlebar button.titlebutton {
  border: none;
  font-size: 0;
  height: 0;
  margin: 0;
  max-height: 0;
  min-height: 0;
  padding: 0;
}