Describe the bug
When we scroll mouse, content not follow by step.

To Reproduce
Steps to reproduce the behavior:
- Use new Modern templete
- See error
Expected behavior
It will be look good like default templete

Screenshots
If applicable, add screenshots to help explain your problem.
Context (please complete the following information):
- Browser: [e.g. chrome, safari, edge]
- Form factor: [e.g. desktop, mobile]
- Docfx version: 2.63.0
- Template: [e.g. default, statictoc]
Additional context
Add any other context about the problem here.