.joe_header__above-logo{
    overflow:hidden;
    display: block;
}
/* 这一步是为了弹性布局，照着写就行啦，不然手机端出错。 */
.joe_header__above-logo:before {
  content: "";
  position: absolute;
  top: -50px;
  left: -15px;
  width: 250px;
  height: 12px;/**光标的宽度，可根据实际调整（建议默认）**/
  background-color: rgba(255,255,255,.5);
  -webkit-transform: rotate(-45deg);
  -moz-transform: rotate(-45deg);
  -ms-transform: rotate(-45deg);
  -o-transform: rotate(-45deg);
  transform: rotate(-45deg);
  -webkit-animation: flashlights 1s ease-in 1s infinite;
  -o-animation: flashlights 1s ease-in 1s infinite;
  animation: flashlights 1.5s ease-in 1s infinite;/**1.5数字参数控制扫光速度，数字越大越慢，默认也是可以的。**/
}
@-webkit-keyframes flashlights {
  0% { left: -100px; top: 0; }
  to { left: 120px; top: 100px; }
}
@-o-keyframes flashlights {
  0% { left: -100px; top: 0; }
  to { left: 120px; top: 100px; }
}
@-moz-keyframes flashlights {
  0% { left: -100px; top: 0; }
  to { left: 120px; top: 100px; }
}
@keyframes flashlights {
  0% { left: -100px; top: 0; }
  to { left: 120px; top: 100px; }
}