Hi everyone,

I wanted to report a UI issue I've been experiencing consistently on the Checkstyle website. Whenever I navigate to any subpage (for example: clicking on "Configuration", "Javadoc Checks", or other sidebar links), the entire main content panel flickers noticeably. The issue involves the panel rapidly resizing --- it grows larger and then shrinks back to normal within a second or two.

This behavior is visually disruptive, especially on desktop. It seems like the layout re-renders or recalculates dimensions on each internal page load, possibly due to a transition effect or glitch.

Steps to reproduce:

1. Go to https://checkstyle.org

2. Click on any sidebar link

3. Observe the main content panel flicker and change size for a moment before stabilizing.