Chapter numbers in CSS

chapters.css

body {
    counter-reset: chapter; /* create a chapter counter scope */
}
h1:before {
    content: "Chapter " counter(chapter) ". ";
    counter-increment: chapter; /* add 1 to chapter */
}
h1 {
    counter-reset: subchapter; /* set section to 0 */
}
h2:before {
    content: counter(chapter) "." counter(subchapter) " ";
    counter-increment: subchapter;
}
h2 {
	counter-reset: section;
}
h3:before {
    content: counter(chapter) "." counter(subchapter) "." counter(section) " ";
    counter-increment: section;
}
h3 {
	counter-reset: subsection;
}
h4:before {
	content: counter(chapter) "." counter(subchapter) "." counter(section) "." counter(subsection) " ";
	counter-increment: subsection;
}
h4 {
	counter-reset: subsubsection;
}
h5:before {
	content: counter(chapter) "." counter(subchapter) "." counter(section) "." counter(subsection) "." counter(subsubsection) " ";
	counter-increment: subsubsection;
}
h5 {
	counter-reset: subsubsubsection;
}
h6:before {
	content: counter(chapter) "." counter(subchapter) "." counter(section) "." counter(subsection) "." counter(subsubsection) "." counter(subsubsubsection) " ";
	counter-increment: subsubsubsection;
}