MediaWiki:CodeblockLineNumbers.css

pre ol { list-style: none !important; counter-reset: lines; border-left: 1px solid rgba(125, 125, 125, 0.5); }

pre ol li { text-indent: -4ch; margin-left: -0.5ch; padding-left: 0.5ch; }

pre ol li::before { width: 3ch; color: #718184; display: inline-block; margin-right: 0.5ch; padding-right: 0.5ch; text-align: right; content: counter(lines); counter-increment: lines; user-select: none; -webkit-user-select: none; }