.banner_thumb {
  position: relative;
  overflow: hidden;
}
.banner_thumb::before {
  background: rgba(255, 255, 255, 0.3);
  bottom: 0;
  content: "";
  left: 50%;
  position: absolute;
  right: 51%;
  top: 0;
  opacity: 1;
  pointer-events: none;
}
.banner_thumb:after {
  background: rgba(255, 255, 255, 0.6);
  bottom: 50%;
  content: "";
  left: 0;
  position: absolute;
  right: 0;
  top: 50%;
  opacity: 1;
  pointer-events: none;
}
.banner_thumb:hover::before {
  left: 0;
  right: 0;
  opacity: 0;
  -webkit-transition: all 900ms linear;
  transition: all 900ms linear;
}
.banner_thumb:hover::after {
  top: 0;
  bottom: 0;
  opacity: 0;
  -webkit-transition: all 900ms linear;
  transition: all 900ms linear;
}