.message {
  text-align: center;
  display: inline-block;
  vertical-align: middle;
}

#main {
  width: 297px;
  height: 298px;
  text-align: center;
}

#mask {
  width: 297px;
  margin: 0 auto;
  background-color: yellow;
  z-index: -1;
}

#per {
  font-size: 22px;
  line-height: 30px;
  position: fixed;
  left: 48%;
  top: 26%;
}

#bulb {
  width: 297px;
  height: 298px;
  cursor: pointer;
  background: url(../bulb.png);
  background-size: cover;
  transform: scaleY(-1);
  z-index: 1;
}

#prize {
  display: none;
  background: url(http://i.imgur.com/RV2eFAV.jpg?1) no-repeat;
  width: 1184px;
  height: 759px;
  position: absolute;
  margin-top: -379px;
  margin-left: -592px;
  left: 50%;
  top: 50%;
  z-index: 99;
}

#sound {
  display: none;
}

.block-center {
  width: 100%;
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  text-align: center;
  z-index: -1;
}

.block-center:before {
  content: ' ';
  display: inline-block;
  vertical-align: middle;
  height: 100%;
}