/* Pin #app to viewport top — survives body padding / injected nodes above #app */
html, body {
  margin: 0 !important;
  padding: 0 !important;
  height: 100% !important;
  width: 100% !important;
  overflow: hidden !important;
  position: relative !important;
  top: 0 !important;
}

#app {
  position: fixed !important;
  top: 0 !important;
  left: 0 !important;
  right: 0 !important;
  bottom: 0 !important;
  width: 100% !important;
  height: 100% !important;
  margin: 0 !important;
  padding: 0 !important;
  overflow: hidden !important;
  /* 不要设 z-index，否则 body 上的遮罩会盖住 #app 内的弹窗 */
  z-index: auto !important;
}