{# Overrides sphinx_book_theme/components/page-toc.html. The book theme copies this component from the pydata theme only to make the title configurable, but its copy drops the `bd-toc-nav` class that the pydata theme puts on the

. That class is what `data-bs-spy`/`data-bs-target` on points at, so without it Bootstrap ScrollSpy finds no target: no TOC link is ever marked active, the pydata script that mirrors `.active` onto the parent

matches nothing, and the CSS rule that expands the active section's subsections (`.bd-toc .nav > .active > ul`) never applies. Restoring the class re-enables both the current-heading highlight and the expansion of the active section. Drop this file if the book theme fixes its copy upstream. -#} {% set page_toc = generate_toc_html() %} {%- if page_toc | length >= 1 %} {%- set page_navigation_heading_id = unique_html_id("pst-page-navigation-heading") -%}

{%- endif %}