ant-design/components/style/core/motion/slide.less

.slide-motion(@className, @keyframeName) {
  @name: ~'@{ant-prefix}-@{className}';
  .make-motion(@name, @keyframeName);
  .@{name}-enter,
  .@{name}-appear {
    opacity: 0;
    animation-timing-function: @ease-out-quint;
  }
  .@{name}-leave {
    animation-timing-function: @ease-in-quint;
  }
}

.slide-motion(slide-up, antSlideUp);
.slide-motion(slide-down, antSlideDown);
.slide-motion(slide-left, antSlideLeft);
.slide-motion(slide-right, antSlideRight);

@keyframes antSlideUpIn {
  0% {
    transform: scaleY(0.8);
    transform-origin: 0% 0%;
    opacity: 0;
  }

  100% {
    transform: scaleY(1);
    transform-origin: 0% 0%;
    opacity: 1;
  }
}

@keyframes antSlideUpOut {
  0% {
    transform: scaleY(1);
    transform-origin: 0% 0%;
    opacity: 1;
  }

  100% {
    transform: scaleY(0.8);
    transform-origin: 0% 0%;
    opacity: 0;
  }
}

@keyframes antSlideDownIn {
  0% {
    transform: scaleY(0.8);
    transform-origin: 100% 100%;
    opacity: 0;
  }

  100% {
    transform: scaleY(1);
    transform-origin: 100% 100%;
    opacity: 1;
  }
}

@keyframes antSlideDownOut {
  0% {
    transform: scaleY(1);
    transform-origin: 100% 100%;
    opacity: 1;
  }

  100% {
    transform: scaleY(0.8);
    transform-origin: 100% 100%;
    opacity: 0;
  }
}

@keyframes antSlideLeftIn {
  0% {
    transform: scaleX(0.8);
    transform-origin: 0% 0%;
    opacity: 0;
  }

  100% {
    transform: scaleX(1);
    transform-origin: 0% 0%;
    opacity: 1;
  }
}

@keyframes antSlideLeftOut {
  0% {
    transform: scaleX(1);
    transform-origin: 0% 0%;
    opacity: 1;
  }

  100% {
    transform: scaleX(0.8);
    transform-origin: 0% 0%;
    opacity: 0;
  }
}

@keyframes antSlideRightIn {
  0% {
    transform: scaleX(0.8);
    transform-origin: 100% 0%;
    opacity: 0;
  }

  100% {
    transform: scaleX(1);
    transform-origin: 100% 0%;
    opacity: 1;
  }
}

@keyframes antSlideRightOut {
  0% {
    transform: scaleX(1);
    transform-origin: 100% 0%;
    opacity: 1;
  }

  100% {
    transform: scaleX(0.8);
    transform-origin: 100% 0%;
    opacity: 0;
  }
}