app/node_modules/ng-zorro-antd/notification/style/placement.less

.@{notification-prefix-cls} {
  &-top,
  &-bottom {
    margin-right: 0;
    margin-left: 0;
  }

  &-top {
    .@{notification-prefix-cls}-fade-enter.@{notification-prefix-cls}-fade-enter-active,
    .@{notification-prefix-cls}-fade-appear.@{notification-prefix-cls}-fade-appear-active {
      animation-name: NotificationTopFadeIn;
    }
  }

  &-bottom {
    .@{notification-prefix-cls}-fade-enter.@{notification-prefix-cls}-fade-enter-active,
    .@{notification-prefix-cls}-fade-appear.@{notification-prefix-cls}-fade-appear-active {
      animation-name: NotificationBottomFadeIn;
    }
  }

  &-topLeft,
  &-bottomLeft {
    margin-right: 0;
    margin-left: @notification-margin-edge;

    .@{notification-prefix-cls}-fade-enter.@{notification-prefix-cls}-fade-enter-active,
    .@{notification-prefix-cls}-fade-appear.@{notification-prefix-cls}-fade-appear-active {
      animation-name: NotificationLeftFadeIn;
    }
  }
}

@keyframes NotificationTopFadeIn {
  0% {
    margin-top: -100%;
    opacity: 0;
  }

  100% {
    margin-top: 0;
    opacity: 1;
  }
}

@keyframes NotificationBottomFadeIn {
  0% {
    margin-bottom: -100%;
    opacity: 0;
  }

  100% {
    margin-bottom: 0;
    opacity: 1;
  }
}

@keyframes NotificationLeftFadeIn {
  0% {
    right: @notification-width;
    opacity: 0;
  }

  100% {
    right: 0;
    opacity: 1;
  }
}