fix(ui): prevent double vertical scrollbars in latex math rendering

[Siddhu2k04]

Fix duplicate vertical scrollbar when LaTeX rendering is enabled

Summary

This PR fixes an issue where enabling latex=true in config.toml could cause two vertical scrollbars to appear in the chat UI when rendering LaTeX content.

Root Cause

The chat interface already provides a scrollable container for messages. When LaTeX content is rendered, the math wrapper may introduce additional overflow behavior, creating a nested scroll container and resulting in duplicate vertical scrollbars.

Changes

• Removed unnecessary vertical overflow handling from LaTeX rendering containers.

• Restricted LaTeX elements to horizontal scrolling only when needed.

• Ensured the main chat container remains the sole vertical scroll region.

• Preserved existing LaTeX rendering behavior and layout.

Before

• latex=true enabled.

• Sending multiple messages containing LaTeX equations eventually displays two vertical scrollbars.

After

• Only one vertical scrollbar is displayed.

• LaTeX equations render correctly.

• Normal chat scrolling behavior remains unchanged.

Testing

Reproduction Steps

1. Enable latex=true in config.toml.

2. Run the following application:

import chainlit as cl
@cl.on_message

async def main(message: cl.Message):

await cl.Message(

content="Here is the quadratic formula:\n$$x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$$"

).send()

3. Start Chainlit.

4. Send messages multiple times until the chat becomes scrollable.

Results

Scenario	Result
Before Fix	Two vertical scrollbars appear
After Fix	Only one vertical scrollbar appears

References

• Fixes UI displays two vertical scrollbars with enabled latex rendering #2949

• Related to UI displays two vertical scrollbars whenever a custom element is rendered #2003

[cubic-dev-ai]

No issues found across 1 file

_{Re-trigger cubic}

[Siddhu2k04]

Hi @asvishnyakov and @sandangel,

I've submitted a fix for #2949 and verified that it resolves the duplicate vertical scrollbar issue when LaTeX rendering is enabled.

Could you please review the PR when you have a chance? Any feedback is appreciated.

Thanks! 🚀