@media screen and (max-width: 768px) {
  .yun-center {
    padding-left: 4vw;
    padding-right: 4vw;
  }
  .yun404 .mian-404 {
    padding-top: 108px;
    width: 80vw;
  }
  .yun404 .mian-404 .pic {
    max-width: 300px;
    background-size: 100% auto;
    width: auto;
  }
  .yun404 .mian-404 .sorry,
  .yun404 .mian-404 .back,
  .yun404 .mian-404 .can {
    font-size: 12px;
    line-height: 1.5;
  }
}