Why does my store have a horizontal scroll on mobile, and can you fix it?

That sideways scroll on phones is almost always one element wider than the viewport, a fixed width: 600px, a 100vw that ignores the scrollbar, an image with no max-width: 100%, or a long unbroken string. We find the offender in DevTools, clamp it with min-width: 0, max-width: 100% and overflow-wrap: anywhere, then confirm zero horizontal scroll at 320, 375 and 390 px. Yes, this is one of the most common fixes we ship.