see attached video.
- tabbox is not scrollable since it doesn't render left/right arrow button for scrolling.
- it renders a label on a tab as ellipsis instead of a complete text.
tabbox is scrollable
Safari 12 has no such issue.
it's a Safari 9 flex bug, please see https://github.com/philipwalton/flexbugs#flexbug-1
Safari fixed the bug after Safari 10 see https://bugs.webkit.org/show_bug.cgi?id=146020
default flex set the flex items with flex-shrink: 1; , add flex:none; or flex-shrink: 0; in flex items will fix the problem.