.tree { line-height: 2 } .tree, .tree ul { list-style: none } .tree li { position: relative } .tree, .tree ul { overflow: hidden; padding-left: 1.5em } .tree li::before { border: solid lightgray; border-width: 0 0 1px 2px; content: ""; height: 1000em; left: -1.5em; position: absolute; top: -1000em + 1em; width: 1em }