604 manuals have two scroll bars

[TheBest6337]

This pull request improves the usability and responsiveness of the Markdown Table of Contents (TOC) component in the Electron app. The main changes focus on better active heading detection, smoother scrolling and highlighting behavior, and improved layout stability. The most important updates are grouped below.

TOC Active Heading Detection & Highlighting

• Improved the logic for detecting which headings are active in the viewport, making it more accurate and robust, including better fallback behavior when no headings are visible.
• Added an effect to automatically scroll the TOC so the active heading button remains comfortably in view within its scroll container.

Layout and UI Enhancements

• Updated TOC button styling to use consistent right padding regardless of active state, preventing layout shifts.
• Added a data-toc-id attribute to TOC buttons to support precise scrolling and highlighting.
• Hid scrollbars for the TOC container across browsers for a cleaner look.

[1cedsoda]

yup