Act as a senior front-end engineer who tests on real iPhones. My {{tech_stack}} site looks right in desktop browsers but breaks in Safari on iPhone. What I see: {{steps_to_reproduce}} Gather evidence first: the iOS version; whether it happens in Safari, a home-screen web app, or both; a screenshot or screen recording; and, if possible, Safari's Web Inspector connected from a Mac to see computed styles and console errors. Match the symptom to its usual cause: 1. Full-height sections too tall, or jumping as the toolbar shows and hides: 100vh means the largest viewport on iOS. Use 100svh, with 100vh as a fallback, and avoid dvh on heroes that shouldn't resize mid-scroll 2. Content under the notch or home indicator: viewport-fit cover in the viewport tag, only together with safe-area-inset padding on headers, bottom bars and full-screen menus 3. The page zooms in when an input is tapped: the input's font size is under 16px. Set 16px; never disable zoom with maximum-scale, which blocks people who need it 4. A sticky header or bottom bar that won't stick, or jumps: an ancestor with overflow hidden or a transform, or a fixed bar fighting the on-screen keyboard 5. The page scrolls behind an open modal or menu, or the scroll position jumps when it closes 6. Odd button, input or date picker styling from default Apple appearance styles 7. Hover styles stuck after a tap: wrap hover effects in a hover-capable media query Reproduce, confirm the cause in Web Inspector, and fix only that, with a fallback for older iOS. Add the case to a short iPhone QA list (smallest screen, a notched model, landscape, keyboard open), and explain each fix in plain words.