Clean mobile app UI screenshot, vertical phone screen 3:4: a Singles Day flash sale app home screen, top status bar with 9:41 and battery, large red countdown timer '00:23:41' with label 'FLASH SALE ENDS IN', hero banner with a gold '11.11' badge, two product cards with product photos, prices and discount tags, a red 'Grab Now' button, bottom navigation bar with Home, Deals, Cart and Profile icons, white background, red and gold accents, crisp typography, aligned grid, no real brand logos, no watermark.