nutui/miniprogram_dev/components/packages/overlay/index.wxss

.overlay-fade-enter-active,
.overlay-fade-leave-active {
  transition: opacity 0.5s ease;
}

.overlay-fade-enter-from,
.overlay-fade-leave-to {
  opacity: 0;
}

.nut-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.7);
}

.nut-overflow-hidden {
  overflow: hidden !important;
}