app/node_modules/ng-zorro-antd/tree/style/rtl.less

@import '../../style/themes/index';
@import '../../style/mixins/index';
@import '../../checkbox/style/mixin';

@tree-prefix-cls: ~'@{ant-prefix}-tree';
@select-tree-prefix-cls: ~'@{ant-prefix}-select-tree';
@tree-node-prefix-cls: ~'@{tree-prefix-cls}-treenode';

.@{tree-prefix-cls} {
  &-rtl {
    direction: rtl;
    .@{tree-prefix-cls}-node-content-wrapper[draggable='true'] {
      .@{tree-prefix-cls}-drop-indicator {
        &::after {
          right: -6px;
          left: unset;
        }
      }
    }
  }

  // ===================== TreeNode =====================
  .@{tree-node-prefix-cls} {
    &-rtl {
      direction: rtl;
    }
  }

  // >>> Switcher
  &-switcher {
    &_close {
      .@{tree-prefix-cls}-switcher-icon {
        svg {
          .@{tree-prefix-cls}-rtl & {
            transform: rotate(90deg);
          }
        }
      }
    }
  }
  // ==================== Show Line =====================
  &-show-line {
    // ================ Indent lines ================
    .@{tree-prefix-cls}-indent {
      &-unit {
        &::before {
          .@{tree-prefix-cls}-rtl& {
            right: auto;
            left: -(@tree-title-height / 2) - 1px;
            border-right: none;
            border-left: 1px solid @border-color-base;
          }
        }
      }
    }
  }
  // >>> Checkbox
  &-checkbox {
    .@{tree-prefix-cls}-rtl & {
      margin: ((@tree-title-height - @checkbox-size) / 2) 0 0 8px;
    }
  }
}

.@{select-tree-prefix-cls} {
  // >>> Checkbox
  &-checkbox {
    .@{tree-prefix-cls}-select-dropdown-rtl & {
      margin: ((@tree-title-height - @checkbox-size) / 2) 0 0 8px;
    }
  }
}