app/node_modules/ng-zorro-antd/style/mixins/compact-item.less

.compact-item-border-radius(@prefix-cls, @bordered-item-cls: null) {
  & when (@bordered-item-cls = null) {
    // border-radius
    &-item:not(&-first-item):not(&-last-item).@{prefix-cls} {
      border-radius: 0;
    }

    &-item.@{prefix-cls}&-first-item:not(&-last-item):not(&-item-rtl) {
      border-top-right-radius: 0;
      border-bottom-right-radius: 0;
    }

    &-item.@{prefix-cls}&-last-item:not(&-first-item):not(&-item-rtl) {
      border-top-left-radius: 0;
      border-bottom-left-radius: 0;
    }

    // ----------rtl for first item----------
    &-item.@{prefix-cls}&-item-rtl&-first-item:not(&-last-item) {
      border-top-left-radius: 0;
      border-bottom-left-radius: 0;
    }

    // ----------rtl for last item----------
    &-item.@{prefix-cls}&-item-rtl&-last-item:not(&-first-item) {
      border-top-right-radius: 0;
      border-bottom-right-radius: 0;
    }
  }

  & when (not (@bordered-item-cls = null)) {
    // border-radius
    &-item:not(&-first-item):not(&-last-item).@{prefix-cls} .@{bordered-item-cls} {
      border-radius: 0;
    }

    &-item&-first-item.@{prefix-cls}:not(&-last-item):not(&-item-rtl) .@{bordered-item-cls} {
      border-top-right-radius: 0;
      border-bottom-right-radius: 0;
    }

    &-item&-last-item.@{prefix-cls}:not(&-first-item):not(&-item-rtl) .@{bordered-item-cls} {
      border-top-left-radius: 0;
      border-bottom-left-radius: 0;
    }

    // ----------rtl for first item----------
    &-item.@{prefix-cls}&-first-item&-item-rtl:not(&-last-item) .@{bordered-item-cls} {
      border-top-left-radius: 0;
      border-bottom-left-radius: 0;
    }

    // ----------rtl for last item----------
    &-item.@{prefix-cls}&-last-item&-item-rtl:not(&-first-item) .@{bordered-item-cls} {
      border-top-right-radius: 0;
      border-bottom-right-radius: 0;
    }
  }
}

.compact-item-border(@prefix-cls, @bordered-item-cls: null, @special-open-cls) {
  & when (@bordered-item-cls = null) {
    // border collapse
    &-item:not(&-last-item):not(&-item-rtl) {
      margin-right: -@border-width-base;
    }

    // rtl border collapse
    &-item:not(&-last-item)&-item-rtl {
      margin-left: -@border-width-base;
    }

    &-item {
      &:hover,
      &:focus,
      &:active {
        z-index: 2;
      }

      // Select has an extra focus className
      & when (not (@special-item-cls = null)) {
        &.@{special-item-cls} {
          z-index: 2;
        }
      }

      &[disabled] {
        z-index: 0;
      }
    }
  }

  & when (not (@bordered-item-cls = null)) {
    // border collapse
    &-item:not(&-last-item) {
      margin-right: -@border-width-base;

      &.@{prefix-cls}-compact-item-rtl {
        margin-right: 0;
        margin-left: -@border-width-base;
      }
    }

    &-item {
      &:hover,
      &:focus,
      &:active {
        > * {
          z-index: 2;
        }
      }

      // Select has an special focus-item
      & when (not (@special-item-cls = null)) {
        &.@{special-item-cls} > * {
          z-index: 2;
        }
      }

      &[disabled] > * {
        z-index: 0;
      }
    }
  }
}

.compact-item(@prefix-cls, @bordered-item-cls: null, @special-item-cls: null) {
  &-compact {
    .compact-item-border(@prefix-cls, @bordered-item-cls, @special-item-cls);

    .compact-item-border-radius(@prefix-cls, @bordered-item-cls);
  }
}