amis/scss/components/form/_nested-select.scss

.#{$ns}NestedSelect {
  position: relative;
  @include input-border();
  &-optionArrowRight {
    display: inline-block;
    padding-right: px2rem(10px);

    svg {
      width: px2rem(12px);
      height: px2rem(12px);
      fill: var(--Form-input-iconColor);
    }
  }

  &-menuOuter {
    display: flex;
  }

  &-noResult {
    width: px2rem(160px);
    padding: 0 var(--gap-xs);
    color: var(--Form-select-placeholderColor);
    line-height: var(--Form-input-lineHeight);
    font-size: var(--Form-select-input-fontSize);
    user-select: none;
    padding: calc(
        (
            var(--Form-select-menu-height) - var(--Form-input-lineHeight) *
              var(--Form-input-fontSize)
          ) / 2
      )
      var(--Form-select-paddingX);
  }

  &-menu {
    width: px2rem(160px);
    height: px2rem(175px); // 高度写死，否则有可能会上下闪动
    background: var(--Form-select-menu-bg);
    color: var(--Form-select-menu-color);
    border: var(--Form-select-outer-borderWidth) solid
      var(--Form-input-onFocused-borderColor);
    box-shadow: var(--Form-select-outer-boxShadow);
    overflow-y: auto;
    overflow-x: hidden;

    &:not(:first-child) {
      border-left: 0;
    }

    .#{$ns}NestedSelect-option {
      position: relative;
      padding-left: var(--gap-md);
      min-height: var(--Form-input-height);
      line-height: var(--Form-input-height);
      cursor: pointer;
      display: flex;

      > .#{$ns}NestedSelect-optionLabel {
        flex: 1;

        &.is-disabled {
          cursor: not-allowed;
          color: var(--text--muted-color);
        }
      }

      &.is-active {
        color: var(--Form-select-menu-onActive-color);
        background: var(--Form-select-menu-onActive-bg);
      }

      &:hover {
        color: var(--Form-select-menu-onHover-color);
        background: var(--Form-select-menu-onHover-bg);
      }

      &:hover > .#{$ns}NestedSelect-childrenOuter {
        display: block;
      }

      &.checkall {
        border-bottom: px2rem(1px) solid #eceff8;
      }
    }
  }
}