JSFiddle - React, Tailwind, and code Playground
by whelkaholism
HTML
<span class="tn">
<span class="tn"><label>1</label></span>
<span class="tn">
<label>2</label>
<span class="tn"><label>2.1</label></span>
<span class="tn"><label>2.2</label></span>
<span class="tn">
<label>2.3</label>
<span class="tn"><label>2.3.1</label></span>
<span class="tn"><label>2.3.2</label></span>
</span>
</span>
<span class="tn"><label>3</label></span>
</span>
CSS
.tn {
display: block;
line-height: 1em;
}
.tn label {
display: inline-block;
line-height: 1em;
}
.tn > .tn {
margin-left: 1em;
}
.tn > .tn:before {
display: inline-block;
content: ' ';
height: 1em;
width: 0.5em;
border-right: 1px solid #000000;
}
.tn > .tn:first-child:before {
}
}