/* 外层只负责整幅画面缩放；1280×720内部视口决定所有窗口、字体和弹窗布局。 */
html,body{margin:0;width:100%;height:100%;overflow:hidden;background:#050807}
#gameViewportHost{position:fixed;top:env(safe-area-inset-top,0px);right:env(safe-area-inset-right,0px);bottom:env(safe-area-inset-bottom,0px);left:env(safe-area-inset-left,0px);overflow:hidden}
#gameViewport{position:absolute;border:0;margin:0;width:1280px;height:720px;transform-origin:top left;display:block;background:#121914;outline:0}