[sunt05]

Summary

On phone-width screens neither docs sidebar opened: the site-navigation and "on this page" toggles did nothing.

sphinx-book-theme 1.4.0 pins pydata-sphinx-theme 0.20.0, which adds a search field to the top navbar whenever navbar_persistent is not set. That renders the PyData header, with its own hidden copies of both sidebar toggles, ahead of the book theme's visible ones. The theme JavaScript binds to the first .primary-toggle / .secondary-toggle on the page, so the hidden buttons got the handlers and the visible ones did nothing.

Changes

• docs/source/conf.py: set navbar_persistent=[], the same default the book theme's own fix applies (fix: don’t show navbar if the user doesn’t ask for it executablebooks/sphinx-book-theme#987, merged after 1.4.0, not yet released).
• pyproject.toml: pin sphinx-book-theme==1.4.0 in the docs extra, so the theme pair, and the markup the toggles depend on, only changes deliberately.

Verification

Docs built with the gallery off and checked in a headless browser:

• 375x812: one toggle of each kind per page; both sidebars open on tap; the search button opens its dialog; the colour-mode menu switches light, dark and auto.
• 1280 wide: the extra top bar that held only a duplicate search field is gone; toggle behaviour matches the book theme's own docs.

The published 2026.6.5 docs pick this up only when the docs anchor is rebuilt.

[github-actions]

CI Build Plan

Changed Files

Documentation (2 files)

• docs/source/conf.py
• pyproject.toml

pyproject.toml (1 file)

• pyproject.toml

Build Configuration

No code build required -- changes are docs/site/non-code only.

Rationale

• No build-triggering changes detected -> builds skipped

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