Copilot Chat side-panel input font is too small and cannot be independently resized

Title:
Copilot Chat side-panel input font is too small and cannot be independently resized

Version:
VS Code 1.125.1 on Linux (x64)
GitHub Copilot Chat installed

Problem:
The Copilot Chat input box in the right-side panel is too small to comfortably use. The text in the dialog/input box is much smaller than the editor text and is difficult to read.

What I expected:
I expected the chat input box font to be independently adjustable, or at least for the panel chat input to respect the configured chat font settings.

What happened:
- Changing chat.fontSize did not reliably enlarge the side-panel input box.
- Changing chat.editor.fontSize affects Chat-in-Editor mode, not the side-panel input.
- Changing window.zoomLevel enlarges the entire UI, which is too broad and makes the rest of the workspace less usable.
- The side-panel input remains too small compared with the rest of the interface.

Repro steps:
1. Open VS Code.
2. Open Copilot Chat in the right-side panel.
3. Try adjusting chat.fontSize and chat.editor.fontSize in settings.
4. Observe that the side-panel input remains too small or behaves inconsistently.
5. Try window.zoomLevel and observe that it affects the entire UI, not just the chat input.

Impact:
This makes the chat input uncomfortable or nearly unusable for long sessions and forces undesirable global UI zoom changes.

Environment:
- Linux
- VS Code 1.125.1
- Copilot Chat side panel
- Workspace-specific and user settings were tested
- .vscode/settings.json was also checked

Notes:
The issue appears to be that the side-panel chat input does not have an independently supported font-size control in this build.