### Begin of the deletion Before filing a report

_Before you file a report, please ensure you are running the latest version of OpenProject and_ 
_have searched for similar bug reports._

###End of the deletion Steps to reproduce

1. Log in as a user with permission to edit Wiki pages in a project.


Begin of the insertion2\.End of the insertion Begin of the deletion      2.End of the deletion Create a new Wiki page.

Begin of the insertion3\.End of the insertion Begin of the deletion      3.End of the deletion Add several headings containing Chinese characters, for example:

```text
## 项目背景

## 需求分析

## 测试计划
```

Begin of the insertion4\.End of the insertion Begin of the deletion      4.End of the deletion Insert the Table of Contents macro (`{{toc}}`) at the top of the page.

Begin of the insertion5\.End of the insertion Begin of the deletion      5.End of the deletion Save the page.

Begin of the insertion6\.End of the insertion Begin of the deletion      6.End of the deletion Click any Chinese entry in the generated TOC.

### What is the buggy behavior?

Clicking a Chinese TOC entry does nothing. The page does not scroll to the corresponding heading, and the anchor link in the address bar is either empty or invalid. TOC navigation works correctly when the headings are pure English (e.g. `## Project Background`), and also works after manually adding an English anchor to a Chinese heading (e.g. `## 项目背景 {#project-background}`). This suggests the issue is in how the TOC macro generates HTML `id` anchors for non-Latin characters, possibly related to slug generation or URL encoding.

<br>

### What is the expected behavior?

_Clicking a Chinese TOC entry should scroll the page to the corresponding heading, the same way it works for English headings. The address bar should show a valid anchor that points to the correct heading._

### **Logs**

_No errors are visible in the browser console when clicking the TOC entry. No relevant errors found in the OpenProject logs._

### Screenshots and other files

* Screenshot of the Wiki page with Chinese headings and the TOC macro.

* Screenshot or screen recording showing the click result.


### Environment information

* OpenProject installation type: Docker installation

* OpenProject version: 17.2

* Browser: Chrome (please replace with your actual browser)

* Operating System: Windows (please replace with your actual OS)

* Language: Browser language: Chinese (Simplified); OpenProject user language: Chinese (Simplified) (please replace with your actual language settings)


**Browser**

* [x] Chrome
* [ ] Firefox
* [ ] Safari
* [ ] Mobile Safari
* [ ] Other (please specify)

**Operating System**

* [x] Windows
* [ ] Mac OS X
* [ ] Mobile iOS
* [ ] Mobile Android
* [ ] Linux (please specify distro)
* [ ] Chrome OS
* [ ] Other (please specify)