.tree {
  font-family: "Courier New", Courier, monospace;
  white-space: nowrap;
}

  .tree ul {
    list-style-type: none;
    padding: 0;
    margin-left: 3em;
    margin-top: 0;
    margin-bottom: 0;
    counter-reset: childIndex;
  }

  .tree li:not(:first-child) {
    counter-increment: childIndex;
  }

  .tree:not(.filter) li::before {
    content: counter(childIndex);
    color: lightgray;
    text-align: right;
    display: inline-block;
    min-width: 2.5em;
    margin-left: -3em;
    padding-right: 0.5em;
  }

  .tree:not(.filter) li.folded > span.numberOfElements::before {
    content: attr(data-item-count);
    display: inline-block;
    margin-left: 0.5em;
    margin-right: 0.5em;
    color: gray;
  }

  .tree li > div.key {
    display: inline;
  }

    .tree li > div.key div.copy {
      display: inline;
      position: relative;
    }

    .tree li > div.key .copy::after {
      content: "\1f4cb";
      opacity: 0.33;
      font-size: 1em;
      background-color: #efefef;
      visibility: hidden;
      display: block;
      position: absolute;
      color: #111;
      transition: background-color 0.5s, visibility 0s 0.3s;
      text-align: center;
      border-radius: 0.2em;
      width: 1.4em;
      height: 1.4em;
      bottom: -0.2em;
      left: 0.2em;
      cursor: pointer;
    }

    .tree li > div.key .copy:hover::after {
      opacity: 1;
      box-shadow: 0 0 3px black;
    }

    .tree li > div.key:hover .copy::after {
      visibility: visible;
      transition: background-color 0.5s, visibility 0s 0.2s;
    }

    .tree li > div.key:hover .copy.copied::after {
      background-color: #0c0;
      transition: background-color 0s;
    }

    .tree li > div.key:hover .copy.not-copied::after {
      background-color: #e55;
      transition: background-color 0s;
    }

    .tree li > div.key > span {
      color: darkslateblue;
    }

      .tree li > div.key > span:hover {
        background-color: lightblue;
      }

  .tree li.folder.folded > ul {
    display: none;
  }

  .tree:not(.filter) li.folder > div.key > span::before {
    content: "\2212";
    opacity: 0.33;
    color: #111;
    background-color: #e0eaef;
    text-align: center;
    display: inline-block;
    width: 1em;
    height: 1em;
    margin-left: -2.9em;
    margin-right: 1.9em;
    cursor: pointer;
    border-radius: 0.2em;
  }

  .tree:not(.filter) li.folder.folded > div.key > span::before {
    content: "+";
  }

  .tree li.folder > div.key:hover > span::before {
    opacity: 1;
  }

  .tree .nullValue {
    color: gray;
    font-weight: bold;
  }

  .tree .numericValue {
    color: darkblue;
    font-weight: bold;
  }

  .tree .stringValue {
    color: brown;
    font-weight: bold;
  }

  .tree span > span.tooltip {
    visibility: hidden;
    color: #111;
    background-color: #fefefe;
    font-weight: normal;
    position: absolute;
    border: 1px solid gray;
    margin-top: 1.5em;
    padding: 0.5em;
    white-space: pre;
    transition-delay: 0.1s;
  }

  .tree span:hover > span.tooltip, span.tooltip:hover {
    visibility: visible;
    transition-delay: 0.2s;
  }

  .tree.filter li.folder.folded > ul {
    display: block;
  }

  .tree.filter li {
    display: none;
  }

    .tree.filter li.filterShow {
      display: block;
    }

  .tree mark {
    background-color: gold;
  }