Yes, the tabs in a tabs pattern should be keyboard navigated using arrow keys (ironically not the Tab key).
Also, the summary for the currently open details element will have the wrong state, 'expanded' instead of 'selected'. And while a set of details can now have a maximum of one open at a time, you can't ensure exactly one is always open (without JavaScript) as the tabs pattern requires.
alt Hacker News
Yes, the tabs in a tabs pattern should be keyboard navigated using arrow keys (ironically not the Tab key).
Also, the summary for the currently open details element will have the wrong state, 'expanded' instead of 'selected'. And while a set of details can now have a maximum of one open at a time, you can't ensure exactly one is always open (without JavaScript) as the tabs pattern requires.