Checklist

• I have searched the existing issues for similar issues.
• I added a very descriptive title to this issue.
• I have provided sufficient information below to help reproduce this issue.

Summary

The white background of the top bar should show up as soon as it contains any element (e.g. st.logo, the sidebar expand/collapse icon, top nav, the toolbar buttons on the right, or the app menu). But in the mega tester app, it's hidden if the sidebar is expanded.

Reproducible Code Example

Steps To Reproduce

1. Just start a basic Streamlit app or go to the mega tester app.
2. Expand the sidebar

Expected Behavior

Top bar has white background.

Current Behavior

Top bar has no background, which makes the toolbar buttons overlap the content:

Note that a) the top bar has a white background if the sidebar is collapsed (probably because of st.logo) and b) the top bar should not have a white background if it doesn't contain anything (e.g. if there's no st.logo, no sidebar, the app menu and toolbar buttons are hidden via config options or the embed parameter).

Is this a regression?

• Yes, this used to work in a previous version.

Debug info

• Streamlit version: 1.46
• Python version:
• Operating System:
• Browser:

Additional Information

No response