.dd { position: relative; display: block; margin: 10px; padding: 0; list-style: none; font-size: 13px; line-height: 20px; }

.dd-list { display: block; position: relative; margin: 0; padding: 0; list-style: none; }
.dd-list .dd-list { padding-left: 30px; }
.dd-collapsed .dd-list { display: none; }

.dd-item,
.dd-empty,
.dd-placeholder { display: block; position: relative; margin: 0; padding: 0;}

.dd-handle {
    display: block;

    margin: 1px 0;
    padding: 8px 10px;
    color: #333;
    text-decoration: none;
    border: 1px solid #ddd;
    background: #fff;
}
.dd-handle:hover { color: var(--primary); background: #fff; }

.dd-item > button { display: block; position: relative; cursor: pointer; float: left; width: 25px; height: 20px; margin: 5px 0; padding: 0; text-indent: 100%; white-space: nowrap; overflow: hidden; border: 0; background: transparent; font-size: 12px; line-height: 1; text-align: center; font-weight: bold; }
.dd-item > button:before { content: '+'; display: block; position: absolute; width: 100%; text-align: center; text-indent: 0; }
.dd-item > button[data-action="collapse"]:before { content: '-'; }

.dd-placeholder { margin: 5px 0; padding: 0; min-height: 30px; background: #f2fbff; border: 1px dashed #b6bcbf; box-sizing: border-box; -moz-box-sizing: border-box; }

.dd-dragel { position: absolute; pointer-events: none; z-index: 9999; }
.dd-dragel > .dd-item .dd-handle { margin-top: 0; }
.dd-dragel .dd-handle {
-webkit-box-shadow: 2px 4px 6px 0 rgba(0,0,0,.1);
box-shadow: 2px 4px 6px 0 rgba(0,0,0,.1);
}