ant-design/style/components/tree.less

@treePrefixCls: ant-tree;
.antCheckboxFn(@checkboxPrefixCls: ant-tree-checkbox);
@import "../mixins/iconfont";
.antTreeSwitcherIcon() {
  position: relative;
  &:after {
    .iconfont-size-under-12px(6px);
    content: '\e60f';
    display: inline-block;
    font-family: 'anticon';
    font-weight: bold;
    position: absolute;
    top: 10px;
    right: 4px;
    color: #666;
    transition: transform .3s ease;
  }
}
.@{treePrefixCls} {
  margin: 0;
  padding: 5px;
  font-size: 12px;
  li {
    padding: 0;
    margin: 0;
    list-style: none;
    white-space: nowrap;
    outline: 0;
    ul {
      margin: 0;
      padding: 0 0 0 18px;
    }
    a {
      display: inline-block;
      padding: 1px 3px 0 0;
      margin: 0;
      cursor: pointer;
      height: 20px;
      text-decoration: none;
      vertical-align: top;
      color: #666;
    }
    span {
      &.@{treePrefixCls}-checkbox {
        margin: 3px 7px 0 0;
      }
      &.@{treePrefixCls}-switcher,
      &.@{treePrefixCls}-iconEle {
        line-height: 0;
        margin: 0;
        width: 16px;
        height: 17px;
        display: inline-block;
        vertical-align: middle;
        border: 0 none;
        cursor: pointer;
        outline: none;
        background-color: transparent;
        background-repeat: no-repeat;
        background-attachment: scroll;
      }
      &.@{treePrefixCls}-switcher {
        &-disabled {
          background: #fff;
          position: relative;
          &:after {
            content: '-';
            position: absolute;
            top: 8px;
            left: 6px;
            color: gray;
          }
        }
        &.@{treePrefixCls}-roots_open,
        &.@{treePrefixCls}-center_open,
        &.@{treePrefixCls}-bottom_open,
        &.@{treePrefixCls}-noline_open {
          .antTreeSwitcherIcon();
        }
        &.@{treePrefixCls}-roots_close,
        &.@{treePrefixCls}-center_close,
        &.@{treePrefixCls}-bottom_close,
        &.@{treePrefixCls}-noline_close {
          .antTreeSwitcherIcon();
          .ie-rotate(3);
          &:after {
            transform: rotate(270deg) scale(0.5);
          }
        }
      }
    }
  }
  &-treenode-disabled {
    >span,
    >a {
      color: gray;
    }
  }
  &-icon__open {
    margin-right: 2px;
    vertical-align: top;
  }
  &-icon__close {
    margin-right: 2px;
    vertical-align: top;
  }
}