When I was using the <window> tag to creating a frameless window, it's always trying to fallback to the classic mode(The Win7 x64 native close/maximize/minimize buttons are appears). I was using the following style to styling the window :root { -moz-appearance: none; background-color: transparent; border: none; font-family: Calibri, Arial, "Microsoft YaHei", SimSun; margin: 0; } _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform