nav {
    counter-reset: toc-chapter;
}

nav h2 {
    counter-increment: none;
}

nav h2::before {
    content: "";
}

nav > ol > li {
    counter-increment: toc-chapter;
    counter-reset: toc-section;
    list-style: none;
}

nav > ol > li > ol > li {
    counter-increment: toc-section;
    counter-reset: toc-subsection;
    list-style: none;
}

nav > ol > li > ol > li > ol > li {
    counter-increment: toc-subsection;
    counter-reset: toc-article;
    list-style: none;
}

nav > ol > li > ol > li > ol > li > ol > li {
    counter-increment: toc-article;
    counter-reset: toc-subarticle;
    list-style: none;
}

nav > ol > li > ol > li > ol > li > ol > li > ol > li {
    counter-increment: toc-subarticle;
    list-style: none;
}

nav > ol > li::before {
    content: "第" counter(toc-chapter, japanese-informal) "章\3000";
}

nav > ol > li > ol > li::before {
    content: "第" counter(toc-section, japanese-informal) "節\3000";
}

nav > ol > li > ol > li > ol > li::before {
    content: "第" counter(toc-subsection, japanese-informal) "小節\3000";
}

nav > ol > li > ol > li > ol > li > ol > li::before {
    content: "第" counter(toc-article, japanese-informal) "条\3000";
}

nav > ol > li > ol > li > ol > li > ol > li > ol > li::before {
    content: "第" counter(toc-subarticle, japanese-informal) "項\3000";
}