从 HTML 树中删除水平空白

Question

我只需要自动删除这棵树中最后三个孙子之间的空格：

* {
  margin: 0;
  padding: 0;
}

.tree ul {
  padding-top: 20px;
  position: relative;

  transition: all 0.5s;
  -webkit-transition: all 0.5s;
  -moz-transition: all 0.5s;
}

.tree li {
  display: inline-block;
  white-space: nowrap;
  vertical-align: top;
  margin: 0 -2px 0 -2px;
  text-align: center;
  list-style-type: none;
  position: relative;
  padding: 20px 5px 0 5px;

  transition: all 0.5s;
  -webkit-transition: all 0.5s;
  -moz-transition: all 0.5s;
}

.tree li::before,
.tree li::after {
  content: '';
  position: absolute;
  top: 0;
  right: 50%;
  border-top: 1px solid #ccc;
  width: 50%;
  height: 20px;
}

.tree li::after {
  right: auto;
  left: 50%;
  border-left: 1px solid #ccc;
}

.tree li:only-child::after,
.tree li:only-child::before {
  display: none;
}

.tree li:only-child {
  padding-top: 0;
}

.tree li:first-child::before,
.tree li:last-child::after {
  border: 0 none;
}

.tree li:last-child::before {
  border-right: 1px solid #ccc;
  border-radius: 0 5px 0 0;
  -webkit-border-radius: 0 5px 0 0;
  -moz-border-radius: 0 5px 0 0;
}

.tree li:first-child::after {
  border-radius: 5px 0 0 0;
  -webkit-border-radius: 5px 0 0 0;
  -moz-border-radius: 5px 0 0 0;
}

.tree ul ul::before {
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  border-left: 1px solid #ccc;
  width: 0;
  height: 20px;
}

.tree li a {
  border: 1px solid #ccc;
  padding: 5px 10px;
  text-decoration: none;
  color: #666;
  font-family: arial, verdana, tahoma;
  font-size: 11px;
  display: inline-block;

  border-radius: 5px;
  -webkit-border-radius: 5px;
  -moz-border-radius: 5px;

  transition: all 0.5s;
  -webkit-transition: all 0.5s;
  -moz-transition: all 0.5s;
}

.tree li a:hover,
.tree li a:hover+ul li a {
  background: #c8e4f8;
  color: #000;
  border: 1px solid #94a0b4;
}

.tree li a:hover+ul li::after,
.tree li a:hover+ul li::before,
.tree li a:hover+ul::before,
.tree li a:hover+ul ul::before {
  border-color: #94a0b4;
}

<link rel='stylesheet' href='style.css'>

<div class="tree">
  <ul>
    <li>
      <a href="#">Parent</a>
      <ul>
        <li>
          <a href="#">Child</a>
          <ul>
            <li>
              <a href="#">Grand Child</a>
            </li>
          </ul>
        </li>
        <li>
          <a href="#">Child</a>
          <ul>
            <li><a href="#">Grand Child</a></li>
            <li>
              <a href="#">Grand Child</a>
              <ul>
                <li>
                  <a href="#">Great Grand Child</a>
                </li>
                <li>
                  <a href="#">Great Grand Child</a>
                </li>
                <li>
                  <a href="#">Great Grand Child</a>
                </li>
              </ul>
            </li>
            <li><a href="#">Grand Child</a></li>
          </ul>
        </li>
      </ul>
    </li>
  </ul>
</div>

目标是在不让“a”元素重叠的情况下尽可能缩小这三个元素，同时将 li 元素相对于直接子元素集中

我有一个由遵循此模型的 R 函数生成的更大的树，因此节点和边可能会发生变化

有一些css或js可以解决这个问题吗？

Answer 1

如果您使用开发工具检查生成的页面，您会看到

li

元素的填充为 5px。 因此，更改它会删除间距：

* {
  margin: 0;
  padding: 0;
}

.tree ul {
  padding-top: 20px;
  position: relative;

  transition: all 0.5s;
  -webkit-transition: all 0.5s;
  -moz-transition: all 0.5s;
}

.tree li {
  display: inline-block;
  white-space: nowrap;
  vertical-align: top;
  margin: 0 -2px 0 -2px;
  text-align: center;
  list-style-type: none;
  position: relative;
  
  
  padding: 20px 0px 0 0px; /* modified */


  transition: all 0.5s;
  -webkit-transition: all 0.5s;
  -moz-transition: all 0.5s;
}

.tree li::before,
.tree li::after {
  content: '';
  position: absolute;
  top: 0;
  right: 50%;
  border-top: 1px solid #ccc;
  width: 50%;
  height: 20px;
}

.tree li::after {
  right: auto;
  left: 50%;
  border-left: 1px solid #ccc;
}

.tree li:only-child::after,
.tree li:only-child::before {
  display: none;
}

.tree li:only-child {
  padding-top: 0;
}

.tree li:first-child::before,
.tree li:last-child::after {
  border: 0 none;
}

.tree li:last-child::before {
  border-right: 1px solid #ccc;
  border-radius: 0 5px 0 0;
  -webkit-border-radius: 0 5px 0 0;
  -moz-border-radius: 0 5px 0 0;
}

.tree li:first-child::after {
  border-radius: 5px 0 0 0;
  -webkit-border-radius: 5px 0 0 0;
  -moz-border-radius: 5px 0 0 0;
}

.tree ul ul::before {
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  border-left: 1px solid #ccc;
  width: 0;
  height: 20px;
}

.tree li a {
  border: 1px solid #ccc;
  padding: 5px 10px;
  text-decoration: none;
  color: #666;
  font-family: arial, verdana, tahoma;
  font-size: 11px;
  display: inline-block;

  border-radius: 5px;
  -webkit-border-radius: 5px;
  -moz-border-radius: 5px;

  transition: all 0.5s;
  -webkit-transition: all 0.5s;
  -moz-transition: all 0.5s;
}

.tree li a:hover,
.tree li a:hover+ul li a {
  background: #c8e4f8;
  color: #000;
  border: 1px solid #94a0b4;
}

.tree li a:hover+ul li::after,
.tree li a:hover+ul li::before,
.tree li a:hover+ul::before,
.tree li a:hover+ul ul::before {
  border-color: #94a0b4;
}

<link rel='stylesheet' href='style.css'>

<div class="tree">
  <ul>
    <li>
      <a href="#">Parent</a>
      <ul>
        <li>
          <a href="#">Child</a>
          <ul>
            <li>
              <a href="#">Grand Child</a>
            </li>
          </ul>
        </li>
        <li>
          <a href="#">Child</a>
          <ul>
            <li><a href="#">Grand Child</a></li>
            <li>
              <a href="#">Grand Child</a>
              <ul>
                <li>
                  <a href="#">Great Grand Child</a>
                </li>
                <li>
                  <a href="#">Great Grand Child</a>
                </li>
                <li>
                  <a href="#">Great Grand Child</a>
                </li>
              </ul>
            </li>
            <li><a href="#">Grand Child</a></li>
          </ul>
        </li>
      </ul>
    </li>
  </ul>
</div>