src/styles/components/tree.less

@tree-prefix-cls: ~"@{css-prefix}tree";
.@{tree-prefix-cls} {
    margin: 0;
    padding: 5px;
    font-size: @font-size-small;
    li {
        padding: 0;
        margin: 8px 0;
        list-style: none;
        white-space: nowrap;
        outline: 0;
        a[draggable],
        a[draggable="true"] {
            user-select: none;
            /* Required to make elements draggable in old WebKit */
            -khtml-user-drag: element;
            -webkit-user-drag: element;
        }
        &.drag-over {
            > a[draggable] {
                background-color: @primary-color;
                color: white;
                opacity: 0.8;
            }
        }
        &.drag-over-gap-top {
            > a[draggable] {
                border-top: 2px @primary-color solid;
            }
        }
        &.drag-over-gap-bottom {
            > a[draggable] {
                border-bottom: 2px @primary-color solid;
            }
        }
        &.filter-node {
            > a {
                color: @error-color!important;
                font-weight: bold!important;
            }
        }
        ul {
            margin: 0;
            padding: 0 0 0 18px;
        }
        a {
            display: inline-block;
            margin: 0;
            padding: 0 4px;
            border-radius: @btn-border-radius-small;
            cursor: pointer;
            text-decoration: none;
            vertical-align: top;
            color: @text-color;
            transition: all @transition-time @ease-in-out;
            &:hover {
                background-color: tint(@primary-color, 90%);
            }
            &.@{tree-prefix-cls}-node-selected {
                background-color: tint(@primary-color, 80%);
            }
        }
        .@{checkbox-prefix-cls}-wrapper{
            margin-right: 4px;
        }
        span {
            &.@{tree-prefix-cls}-switcher,
            &.@{tree-prefix-cls}-iconEle {
                display: inline-block;
                text-align: center;
                width: 16px;
                height: 16px;
                line-height: 16px;
                margin: 0;
                vertical-align: middle;
                border: 0 none;
                cursor: pointer;
                outline: none;
            }
            //&.@{tree-prefix-cls}-icon_loading {
            //    &:after {
            //        display: inline-block;
            //        //.iconfont-font("\e6a1");
            //        animation: loadingCircle 1s infinite linear;
            //        color: @primary-color;
            //    }
            //}
            &.@{tree-prefix-cls}-switcher {
                i{
                    transition: all @transition-time @ease-in-out;
                }
                &.@{tree-prefix-cls}-switcher-noop {
                    cursor: auto;
                    i{
                        display: none;
                    }
                }
                &.@{tree-prefix-cls}-roots_open,
                &.@{tree-prefix-cls}-center_open,
                &.@{tree-prefix-cls}-bottom_open,
                &.@{tree-prefix-cls}-noline_open {
                    i {
                        transform: rotate(90deg);
                    }
                }
                &.@{tree-prefix-cls}-roots_close,
                &.@{tree-prefix-cls}-center_close,
                &.@{tree-prefix-cls}-bottom_close,
                &.@{tree-prefix-cls}-noline_close {
                }
            }
        }
    }
    &-child-tree {
        display: none;
        &-open {
            display: block;
        }
    }
    &-treenode-disabled {
        >span,
        >a,
        >a span {
            color: @input-disabled-bg;
            cursor: not-allowed;
        }
    }
    &-icon__open {
        margin-right: 2px;
        vertical-align: top;
    }
    &-icon__close {
        margin-right: 2px;
        vertical-align: top;
    }
}