TOC dropdown no longer indents headings by level

Summary

In the file preview, the "Table of contents" dropdown renders all headings flat, without indentation to reflect the heading hierarchy.

This appears to have regressed on GitLab.com sometime after July 2026. The same dropdown on snippet pages does not seem to be affected.

Steps to reproduce

  1. Open a Markdown file that has nested headings (e.g. #, ##, ###)
  2. Open the "Table of contents" dropdown above the file preview

Example Project

https://gitlab.com/gitlab-org/gitlab-development-kit/-/blob/main/README.md

image

What is the current bug behavior?

Every item in the dropdown has the same indentation.

What is the expected correct behavior?

Items are indented according to their heading level, as they still are on snippet pages.

Output of checks

This bug happens on GitLab.com

Edited by skkzsh