body{
  position: relative;
}
.confirm-box{
  position: fixed;
  z-index: 1000;
  width: 300px;
  left: 50%;
  margin-left: -150px;
  top: 30%;
  background-color: #fff;
}
.body-mask{
  position: fixed;
  width: 100%;
  height: 100%;
  z-index: 999;
  left: 0;
  right: 0;
  top: 0;
  bottom: 0;
  background: rgba(0,0,0,0.4);
}