MediaWiki:Common.css

#mw-content-text {
  counter-reset: h1;
}

#mw-content-text h1,
#mw-content-text h2,
#mw-content-text h3,
#mw-content-text h4,
#mw-content-text h5,
#mw-content-text h6,
#mw-content-text h7 {
  text-transform: uppercase;
  padding-top: 20px;
  font-weight: bold;
}

/* H1 */
#mw-content-text h1 {
  counter-reset: h2;
  counter-increment: h1;
  font-size: 2em;
}
#mw-content-text h1::before {
  content: counter(h1) ". ";
}

/* H2 */
#mw-content-text h2 {
  counter-reset: h3;
  counter-increment: h2;
  font-size: 1.75em;
  margin-left: 1em;
}
#mw-content-text h2::before {
  content: counter(h1) "." counter(h2) " ";
}

/* H3 */
#mw-content-text h3 {
  counter-reset: h4;
  counter-increment: h3;
  font-size: 1.5em;
  margin-left: 2em;
}
#mw-content-text h3::before {
  content: counter(h1) "." counter(h2) "." counter(h3) " ";
}

/* H4 */
#mw-content-text h4 {
  counter-reset: h5;
  counter-increment: h4;
  font-size: 1.25em;
  margin-left: 3em;
}
#mw-content-text h4::before {
  content: counter(h1) "." counter(h2) "." counter(h3) "." counter(h4) " ";
}

/* H5 */
#mw-content-text h5 {
  counter-reset: h6;
  counter-increment: h5;
  font-size: 1.125em;
  margin-left: 4em;
}
#mw-content-text h5::before {
  content: counter(h1) "." counter(h2) "." counter(h3) "." counter(h4) "." counter(h5) " ";
}

/* H6 */
#mw-content-text h6 {
  counter-reset: h7;
  counter-increment: h6;
  font-size: 1em;
  margin-left: 5em;
}
#mw-content-text h6::before {
  content: counter(h1) "." counter(h2) "." counter(h3) "." counter(h4) "." counter(h5) "." counter(h6) " ";
}

/* Math */
#mw-content-text math {
  border: 1px solid black;
  padding: 20px;
  font-weight: bolder;
  margin: 10px;
}