position: relative;
    background-color: #e0e0e0; /* grey 300 */
    width: 320px;
    height: 240px;
    font: 900 24px Roboto;
}
.red-box {
    background-color: #ef5350; /* red 400 */
    padding: 16px;
    color: #ffffff;

position: absolute;
    top: 24px;
    left: 24px;
}

child: Stack(
    children: [
      Positioned(
        // red box