counter
- http://www.double-team.org/2008/02/22/000053/
<head> <style> body { counter-reset: test; } /* ← */ h1 { counter-increment: test; } h1::before { content: counter(test) ". "; } </style> </head> <body> <div><h1>a</h1></div> <div><h1>b</h1></div> </body>