haowanShow/miniprogram/components/modal/modal.wxss

.modal {
  width: 100%;
  height: 100%;
  position: fixed;
  top: 0;
  left: 0;
  display: flex;
  align-items: center;
  justify-content: center;
}

.mask {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: #000;
  opacity: 0.3;
}

.content {
  position: absolute;
}