Mobile Form UX Problems: How I Fixed Checkout Drop-Off With Better Error States

Last month I worked on a mobile checkout flow that looked fine in Figma but kept losing users at the shipping step. The first version was visually clean: one column, simple inputs, one blue Continue button. In session replay, though, people were tapping the button two or three times, then backing out. Support tickets had the same pattern: "address will not submit" or "I do not know what is wrong…