/* 遮罩和弹窗本体合一 */
#mask.mask {
  display: none;
  position: fixed;
  _position: absolute; /* IE6 fallback */
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  background: #00000065;
  z-index: 9998;
  text-align: center;
}

/* 弹窗内容居中 */
#mask .cover_img {
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  right: 0;
  margin: auto;
  max-width: 50vw;
  max-height: 80vh;
  z-index: 10000;
}

/* 关闭按钮 */
#mask .icon_close {
  position: absolute;
  right: 10vw;
  top: 10vh;
  width: 32px;
  height: 32px;
  cursor: pointer;
  z-index: 10001;
}