Steps to reproduce:

1. Open any article with images on iPad Pro 13" (or iPad Air 13") in landscape orientation
2. Ensure the Table of Contents sidebar is visible in the left column
3. Scroll down (tab bar hides) then scroll back up (tab bar shows)

Expected: Images maintain their size
Actual: Images jump between two sizes on each scroll direction change, disrupting the page layout and causing loss of reading position

Root cause:
When the tab bar hides/shows, adjustedContentInset.top changes, which changes window.innerHeight inside the WKWebView. With the TOC sidebar visible, the web view is 2/3 of the screen width (~917pt on 13" iPads), making the viewport nearly square. The innerHeight change (between ~872 and ~936) flips the CSS @media (orientation:...) query, causing images to toggle between the width:50% (landscape) and width:60% (tablet) PCS rules.

Only affects 13" iPads because on smaller iPads, the 2/3-width web view always exceeds innerHeight, keeping CSS orientation stable.

Affects: iOS 18+, iPad Pro/Air 13", landscape with TOC visible

Test Notes

In TestFlight 7.9.2 (5975)