.toc { position: sticky; top: 100px; } .toc ul { padding: 0; margin: 0; } .toc a { color: #999; font-size: 14px; text-decoration: none; } .toc .toc-h2 { margin-left: 10px } .toc .toc-h3 { margin-left: 20px } .toc li.active { border-left: 2px solid; } .toc li.active a { color: #434462; font-weight: bold; } .toc.right { right: 0 } .toc li { list-style: none; padding: 3px 20px; margin-left: -2px; }