.wiki-content h1
 {
 counter-increment: h1c;
    counter-reset: h2c;
}
.wiki-content h1:before {
    display: marker;
    content: counter(h1c) ". ";
  }
 
.wiki-content h2
{
 counter-increment: h2c;
    counter-reset: h3c;
}
.wiki-content   h2:before {
    display: marker;
    content: counter(h1c) "." counter(h2c) ". ";
  }
 
.wiki-content h3
{
counter-increment: h3c;
    counter-reset: h4c;
}
 
.wiki-content  h3:before {
    display: marker;
    content: counter(h1c) "." counter(h2c) "." counter(h3c) ". ";
  }
 
.wiki-content h4
{
   counter-increment: h4c;
    counter-reset: h5c;
}
.wiki-content  h4:before {
    display: marker;
    content: counter(h1c) "." counter(h2c) "." counter(h3c) ". " counter(h4c) ". ";
  }
 
.wiki-content h5
{
  counter-increment: h5c;
    counter-reset: h6c;
}
.wiki-content  h5:before {
    display: marker;
    content: counter(h1c) "." counter(h2c) "." counter(h3c) ". " counter(h4c) ". " counter(h5c) ". ";
  }
 
.wiki-content h6
{
  counter-increment: h6c;
  }
.wiki-content   h6:before {
    display: marker;
    content: counter(h1c) "." counter(h2c) "." counter(h3c) "." counter(h4c) ". " counter(h5c) ". " counter(h6c) ". ";
  }

h1 Foo

h2 Bar