finish quick demo

Zhao Yuhang

2023-12-18 6500aae0d32383a988aff9fb680d58a851012a14

 examples/mainwindow/dark-style.qss

@@ -16,6 +16,7 @@
    border: none;
    color: #ECECEC;
    background-color: transparent;
    min-height: 28px;
}