* {
  engine: none;
  border-style: none;
  border-image: none;
  background-image: none;
  background-clip: border-box;
  background-repeat: no-repeat;
  border-radius: 0;
}

GtkWindow {
  background-color: rgb(255,255,255);
}

GtkButton {
  border-width: 5;
  border-style: solid;
  border-color: rgba(255,0,0,0.5);
  padding: 10;
  background-color: rgb(0,0,255);

  background-image: url("green-20x20.png");
}

#button1 {
  background-origin: border-box;
  background-clip: border-box;
}
#button2 {
  background-origin: padding-box;
  background-clip: border-box;
}
#button3 {
  background-origin: content-box;
  background-clip: border-box;
}
#button4 {
  background-origin: border-box;
  background-clip: padding-box;
}
#button5 {
  background-origin: padding-box;
  background-clip: padding-box;
}
#button6 {
  background-origin: content-box;
  background-clip: padding-box;
}
#button7 {
  background-origin: border-box;
  background-clip: content-box;
}
#button8 {
  background-origin: padding-box;
  background-clip: content-box;
}
#button9 {
  background-origin: content-box;
  background-clip: content-box;
}

GtkButton#reference {
  border-width: 0;
  background-image: url("reference-background-origin.png");
}