Untitled

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title>Numbered Headings</title>
  </head>
  <body>
    <style>
    body {counter-reset: ebene1;}

    h1:before {
        content: counter(ebene1) " ";
        counter-increment: ebene1;}
    h1 {counter-reset: ebene2;}

    h2:before {
        content: counter(ebene1) "." counter(ebene2) " ";
        counter-increment: ebene2;}
    h2 {counter-reset: ebene3;}

    h3:before {
        content: counter(ebene1) "." counter(ebene2) "." counter(ebene3) " ";
        counter-increment: ebene3;}
    </style>

    <h1>bla</h1>
    <h2>bla</h2>
    <h2>bla</h2>
    <h1>bla</h1>
    <h2>bla</h2>
    <h3>bla</h3>
    <h2>bla</h2>
  </body>
</html>